IGF-1R Signaling Pathway Research Articles

Abstract 23: Caloric restriction slows tumor growth and metastases in both hormone-sensitive and hormone-resistant prostate cancers

Abstract Introduction: The purpose of this study is to assess the effect of caloric restriction (CR) on prostate cancer (PCa) tumor burden, proliferation, and overall survival with and without radiation treatment (RT). Additionally, we determined if the beneficial effect of CR noted are due to a reduction in pro-inflammatory markers hypothesized to enhance PCa tumorgenesis. Methods: To assess the effect of CR in vivo, 40 male 12 week-old NCRNu-M mice were injected with LNCaP or PC3 tumor cells. Once tumors were palpable, mice were randomly assigned to one of four treatment groups in cohorts of 10: ad libitum (AL) diet, 6.5Gy of radiation (RT), 30% reduction in caloric intake (CR), or CR+RT. Tumor growth and proliferation rate were measured 3 times per week via calipers and live bioluminescent imaging. Additionally, PCa tumor tissue were analyzed to determine if CR can exert its effect on tumor growth and metastases via IGF-1R signaling pathway. Results: Adding CR to RT decreased tumor progression. In the PC3 murine model, when compared to AL, RT reduced tumor size by 22%, 77% with CR, and 80% with CR+RT. In the LNCaP murine model, compared with AL, CR reduced tumor size by 49% and a 55% reduction with CR+RT. Primary tumor formation began 9 weeks post tumor injection in the radiated cohort and was delayed to 15 weeks post tumor injection in the CR and CT+ RT cohorts. Additionally, time to metastasis was delayed with CR (86 days to metastasis in AL, 93 with RT, and 108 when combining CR+RT). Molecularly, CR decreased multiple members of the IGF-1R signaling pathway. The total IGF-1 and IGF-1R levels exhibited 50% reduction with CR and CR+RT but total INSR levels. CR also induced a significant decrease of pGSK3β and pAKT levels. Conclusions: For the first time, we have shown that decreasing calories by 30% in both hormone-sensitive and hormone-refractory prostate cancer models, enhance the efficacy of radiation. Our experiments show that even CR alone and in combination with RT can improve PCa tumor proliferation rate, tumor burden, time to metastasis, and overall survival. We hypothesize that these changes are in part, due to the decrease of the IGF-1R signaling pathway. We propose that CR may be used as a novel therapeutic intervention to enhance outcomes of radiation treatment by altering the molecular profile of prostate tumors. Citation Format: Robert S. Gitman, Meredith LaRose, Edouard J. Trabulsi, Ajay Palagani, Tiziana DeAngelis, William K. Kelly, Leonard G. Gomella, Nicole L. Simone. Caloric restriction slows tumor growth and metastases in both hormone-sensitive and hormone-resistant prostate cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 23.

The TGFβ pathway stimulates ovarian cancer cell proliferation by increasing IGF1R levels.

In a search for new therapeutic targets for treating epithelial ovarian cancer, we analyzed the Transforming Growth Factor Beta (TGFβ) signaling pathway in these tumors. Using a TMA with patient samples we found high Smad2 phosphorylation in ovarian cancer tumoral cells, independently of tumor subtype (high-grade serous or endometrioid). To evaluate the impact of TGFβ receptor inhibition on tumoral growth, we used different models of human ovarian cancer orthotopically grown in nude mice (OVAs). Treatment with a TGFβRI&II dual inhibitor, LY2109761, caused a significant reduction in tumor size in all these models, affecting cell proliferation rate. We identified Insulin Growth Factor (IGF)1 receptor as the signal positively regulated by TGFβ implicated in ovarian tumor cell proliferation. Inhibition of IGF1R activity by treatment with a blocker antibody (IMC-A12) or with a tyrosine kinase inhibitor (linsitinib) inhibited ovarian tumoral growth in vivo. When IGF1R levels were decreased by shRNA treatment, LY2109761 lost its capacity to block tumoral ovarian cell proliferation. At the molecular level TGFβ induced mRNA IGF1R levels. Overall, our results suggest an important role for the TGFβ signaling pathway in ovarian tumor cell growth through the control of IGF1R signaling pathway. Moreover, it identifies anti-TGFβ inhibitors as being of potential use in new therapies for ovarian cancer patients as an alternative to IGF1R inhibition.

Metformin restores crizotinib sensitivity in crizotinib-resistant human lung cancer cells through inhibition of IGF1-R signaling pathway.

AimDespite the impressive efficacy of crizotinib for the treatment of ALK-positive non-small cell lung cancer, patients invariably develop therapeutic resistance. Suppression of the IGF-1R signaling pathway may abrogate this acquired mechanism of drug resistance to crizotinib. Metformin, a widely used antidiabetic agent, may reverse crizotinib resistance through inhibition of IGF-1R signaling.ResultsThe present study revealed that metformin effectively increased the sensitivity of both crizotinib-sensitive and -resistant non-small cell lung cancer cells to crizotinib, as evidenced by decreased proliferation and invasion and enhanced apoptosis. Metformin reduced IGF-1R signaling activation in crizotinib-resistant cells. Furthermore, the addition of IGF-1 to crizotinib-sensitive H2228 cells induced crizotinib resistance, which was overcome by metformin.Experimental designThe effects of metformin to reverse crizotinib resistance were examined in vitro by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT), invasion assay, ki67 incorporation assay, flow cytometry analysis, Western blot analysis, and colony-forming assay.ConclusionsMetformin may be used in combination with crizotinib in ALK+ NSCLC patients to overcome crizotinib resistance and prolong survival.

Advances in targeted and immunobased therapies for colorectal cancer in the genomic era.

Targeted therapies require information on specific defective signaling pathways or mutations. Advances in genomic technologies and cell biology have led to identification of new therapeutic targets associated with signal-transduction pathways. Survival times of patients with colorectal cancer (CRC) can be extended with combinations of conventional cytotoxic agents and targeted therapies. Targeting EGFR- and VEGFR-signaling systems has been the major focus for treatment of metastatic CRC. However, there are still limitations in their clinical application, and new and better drug combinations are needed. This review provides information on EGFR and VEGF inhibitors, new therapeutic agents in the pipeline targeting EGFR and VEGFR pathways, and those targeting other signal-transduction pathways, such as MET, IGF1R, MEK, PI3K, Wnt, Notch, Hedgehog, and death-receptor signaling pathways for treatment of metastatic CRC. Additionally, multitargeted approaches in combination therapies targeting negative-feedback loops, compensatory networks, and cross talk between pathways are highlighted. Then, immunobased strategies to enhance antitumor immunity using specific monoclonal antibodies, such as the immune-checkpoint inhibitors anti-CTLA4 and anti-PD1, as well as the challenges that need to be overcome for increased efficacy of targeted therapies, including drug resistance, predictive markers of response, tumor subtypes, and cancer stem cells, are covered. The review concludes with a brief insight into the applications of next-generation sequencing, expression profiling for tumor subtyping, and the exciting progress made in in silico predictive analysis in the development of a prescription strategy for cancer therapy.

GRK2 overexpression inhibits IGF1-induced proliferation and migration of human hepatocellular carcinoma cells by downregulating EGR1

G protein-coupled receptor kinase 2 (GRK2) is a serine/threonine kinase that is involved in a variety of important signaling pathways and alternation of GRK2 protein level or activity causes diseases such as heart failure, rheumatoid arthritis, and obesity. However, the role and mechanism of GRK2 in hepatocellular carcinoma (HCC) progression is not fully investigated. In this study we found that GRK2 plays an inhibitory role in IGF1-induced HCC cell proliferation and migration. Overexpression of GRK2 causes a decrease in early growth response-1 (EGR1) expression, while knockdown of GRK2 leads to marked increase in EGR1 expression in the treatment of IGF1. Through co-immunoprecipitation and western blot assay, we confirmed that GRK2 can interact with insulin-like growth factor 1 receptor (IGF-1R) and inhibits IGF1-induced activation of IGF1R signaling pathway. Silencing EGR1 attenuates GRK2 overexpression-caused inhibition of cell proliferation, tumor colony number and migration activity, while overexpressing of EGR1 restores the anti-proliferative and migratory effect by GRK2 overexpression in HCCLM3 cells. Collectively, these results suggest that GRK2 may inhibit IGF1-induced HCC cell growth and migration through downregulation of EGR1 and indicate that enforced GRK2 may offer a potential therapeutic approach against HCC.

Registered report: A chromatin-mediated reversible drug-tolerant state in cancer cell subpopulations.

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a substantial number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (Errington et al., 2014). This Registered Report describes the proposed replication plan of experiments from "A chromatin-mediated reversible drug-tolerant state in cancer cell subpopulations" by Sharma and colleagues, published in Cell in 2010 (Sharma et al., 2010). Sharma and colleagues demonstrated that prolonged exposure of cancer cells to TKIs give rise to small populations of "drug tolerant persisters" (DTPs) (Figure 1B-C) that were reversed during subsequent maintenance under drug-free conditions (Figures 1E, 2B and 2E). DTPs exhibited reduced histone acetylation and sensitivity to HDAC inhibitors (HDIs) (Figure 4A-B). Drug sensitivity was restored with co-treatment of either HDIs or an IGF-1R inhibitor, in combination with TKIs (Figure 5A-B). Inhibition of IGF-1R activation also led to decreased KDM5A expression and restoration of H3K4 methylation, suggesting a direct link between the IGF-1R signaling pathway and KDM5A function (Figure 7A, 7C, and 7I). The Reproducibility Project: Cancer Biology is a collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife.

Targeting tumor-stroma crosstalk: the example of the NT157 inhibitor.

Recent clinical research has provided evidence that cancer progression and therapy resistance is driven not only by tumor's genetic profile but also by complex paracrine interactions within the tumor microenvironment (TME). The role of TME in modulating tumor drug sensitivity is increasingly recognized and targeting TME has been the focus of novel therapeutic approaches. Two recent reports show that a new anti-cancer drug, the inhibitor NT157 has the potential to inhibit IGF-1R and STAT3 signaling pathways in cancer cells and stroma cells of TME leading to a decrease in cancer cell survival.

Molecular Pathways: Clinical Applications and Future Direction of Insulin-like Growth Factor-1 Receptor Pathway Blockade

The IGF1R signaling pathway is a complex and tightly regulated network that is critical for cell proliferation, growth, and survival. IGF1R is a potential therapeutic target for patients with many different malignancies. This brief review summarizes the results of clinical trials targeting the IGF1R pathway in patients with breast cancer, sarcoma, and non-small cell lung cancer (NSCLC). Therapeutic agents discussed include both monoclonal antibodies to IGF1R (dalotuzumab, figitumumab, cixutumumab, ganitumab, R1507, AVE1642) and newer IGF1R pathway targeting strategies, including monoclonal antibodies to IGF1 and IGF2 (MEDI-573 and BI 836845) and a small-molecule tyrosine kinase inhibitor of IGF1R (linsitinib). The pullback of trials in patients with breast cancer and NSCLC based on several large negative trials is noted and contrasted with the sustained success of IGF1R inhibitor monotherapy in a subset of patients with sarcoma. Several different biomarkers have been examined in these trials with varying levels of success, including tumor expression of IGF1R and its pathway components, serum IGF ligand levels, alternate pathway activation, and specific molecular signatures of IGF1R pathway dependence. However, there remains a critical need to define predictive biomarkers in order to identify patients who may benefit from IGF1R-directed therapies. Ongoing research focuses on uncovering such biomarkers and elucidating mechanisms of resistance, as this therapeutic target is currently being analyzed from the bedside to bench.

Abstract 2711: Regulation of the IGF-1R signaling by angiotensin signaling pathway

Abstract Lung cancer is one of the most commonly diagnosed cancers in the world. Tobacco smoking is the most predominant risk factor for the development of lung cancer. Carcinogenic compounds in tobacco smoke are thought to be responsible for lung cancer, at least in part, by activating G-protein coupled receptor (GPCR)-mediated signaling pathways. GPCR signaling has been suggested to cross-talk with the IGF-1R signaling pathway, a key pathway for cell survival, transformation and growth. However, the mechanisms underlying the crosstalk between GPCR and IGF-1R signaling pathways remain poorly understood. Here we show that tobacco carcinogen (TC) contributes to the lung carcinogenesis by activating the angiotensin signaling and subsequent IGF-1R signaling pathways. We observed that a potent tobacco carcinogen, nitrosamine 4-(methylnitro-samino)-1-(3-pyridyl)-1-butanone (NNK, nicotine-derived nitrosamine ketone), induced transformed phenotypes, including foci formation, viability in the absence of growth factors, and anchorage-dependent and -independent colony formation, and activation of the IGF-1R in normal human bronchial epithelial cells. The NNK treatment also induced lung tumor formation in mice. Losartan, an angiotensin type-1 receptor blocker, and captopril, an angiotensin converting enzyme (ACE) inhibitor, disrupted NNK-induced IGF-1R activation and transformed phenotypes in normal human bronchial epithelial cells and reduced lung tumor formation in mice. These findings indicated that TC-induced angiotensin signaling pathway can enhance lung carcinogenesis by activating the IGF-1R signaling. Our results suggest that targeting IGF-1R by using angiotensin signaling inhibitors may be an effective strategy for the chemoprevention of lung cancer. Citation Format: Hye-Jin Boo, Hyun-Ji Jang, Yujin Jung, Hye-Young Min, Ho-Young Lee. Regulation of the IGF-1R signaling by angiotensin signaling pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2711. doi:10.1158/1538-7445.AM2015-2711

Development of trastuzumab-resistant human gastric carcinoma cell lines and mechanisms of drug resistance.

Trastuzumab has been successfully employed for the treatment of Her-2-positive gastric cancer. However, there are problems with both primary and secondary resistance to trastuzumab. In this study, we employed the human gastric carcinoma cell line NCI-N87 with high Her-2 expression to create trastuzumab-resistant NCI-N87/TR cells by stepwise exposure to increasing doses of trastuzumab. Western blotting and Real-time PCR were conducted to detect protein and gene levels. Compared with NCI-N87 cells, the expression of P-IGF-1R and P-AKT proteins was significantly increased in NCI-N87/TR cells (both P = 0.000), while PTEN gene and protein expression showed a significant decrease (both P = 0.000). In addition, mutations of the PTEN gene were detected at exons 5, 7, and 8. The sensitivity of NCI-N87/TR cells to trastuzumab was increased by transfection with the PTEN gene, or by incubation with a PI3K inhibitor (LY294002) or an IGF-IR inhibitor (AG1024), as well as siRNA targeting PI3K p110 or IGF-1R. Taken together, our findings showed that activation of the PI3K-AKT signaling pathway was one of the major mechanisms leading to resistance of NCI-N87/TR gastric cancer cells to trastuzumab, which was probably associated with PTEN gene down-regulation and mutation, as well as with over-activity of the IGF-1R signaling pathway.

TSH-Mediated TNFα Production in Human Fibrocytes Is Inhibited by Teprotumumab, an IGF-1R Antagonist.

PurposeFibrocytes (FC) are bone marrow-derived progenitor cells that are more abundant and infiltrate the thyroid and orbit in Graves orbitopathy (GO). FCs express high levels of thyrotropin receptor (TSHR) and insulin-like growth factor-1 receptor (IGF-1R). These receptors are physically and functionally associated, but their role in GO pathogenesis is not fully delineated. Treatment of FCs with thyroid stimulating hormone (TSH) or M22 (activating antibody to TSHR) induces the production of numerous cytokines, including tumor necrosis factor α (TNFα). Teprotumumab (TMB) is a human monoclonal IGF-1R blocking antibody currently in clinical trial for GO and inhibits TSHR-mediated actions in FCs.AimTo characterize the molecular mechanisms underlying TSH-induced TNFα production by FCs, and the role of IGF-1R blockade by TMB.DesignFCs from healthy and GD patients were treated with combinations of TSH, M22, MG132 and AKTi (inhibitors of NF-κB and Akt, respectively), and TMB. TNFα protein production was measured by Luminex and flow cytometry. Messenger RNA expression was quantified by real time PCR.ResultsTreatment with TSH/M22 induced TNFα protein and mRNA production by FCs, both of which were reduced when FCs were pretreated with MG132 and AKTi (p<0.0001). TMB decreased TSH-induced TNFα protein production in circulating FCs from mean fluorescent index (MFI) value of 2.92 to 1.91, and mRNA expression in cultured FCs from 141- to 52-fold expression (p<0.0001). TMB also decreased M22-induced TNFα protein production from MFI of 1.67 to 1.12, and mRNA expression from 6- to 3-fold expression (p<0.0001).ConclusionTSH/M22 stimulates FC production of TNFα mRNA and protein. This process involves the transcription factor NF-κB and its regulator Akt. Blocking IGF-1R attenuates TSH/M22-induced TNFα production. This further delineates the interaction of TSHR and IGF1-R signaling pathways. By modulating the proinflammatory properties of FCs such as TNFα production, TMB may be a promising therapeutic agent for GO.

Effect of aspirin on cognitive function and hippocampal IGF-1R/p-IGF-1R expression in rats with diabetic encephalopathy

Objective To investigate the effect of aspirin(Asp)on cognitive function and the insulin-like growth factor-1receptor/phosphorylated insulin-like growth factor-1receptor(IGF-1R/p-IGF-1R)expression in the hippocampus of rats with diabetic encephalopathy,so as to analyze the protective mechanism of aspirin on brain.Methods Diabetes mellitus(DM)was induced by intraperitoneal injection of streptozotocin(STZ,60mg/kg body mass).Rats were randomly assigned to four groups(n=10animals per group),i.e.control,control+ Asp,DM,and DM + Asp groups.One week after the injection of STZ,the animals in Con+Asp and DM+Asp groups were gavaged with aspirin(10 mg/ [kg·d])for 14 weeks.Meanwhile,the control group received the same dose of noromal saline for 14 weeks,and then the cognitive function was observed by Morris water maze(MWM)test in all rats.The expressions of IGF-1Rand p-IGF-1R proteins in the hippocampus of rats were examined by Western blotting analysis.Results The cognitive function of diabetic rats was improved after treated with aspirin:the escape latency of MWM test in DM + Asp group was significantly shorter than that in DM group(P0.01);the number of platform crossing and time spent in the target quadrant in the MWM test were significantly more in DM + Asp group compared with those in DM group(P0.01 or P0.05).H-E result showed that the neurons in DM + Asp group were increased compared with that in DM group.The hippocampal expression of p-IGF-1Rprotein in DM group was significantly lower than that in the control group(P0.01)and aspirin treatment significantly increased p-IGF-1Rexpression(P0.01).However,the IGF-1Rprotein levels in the hippocampus showed no significant difference between different groups.Conclusion Aspirin may protect the brain of rats with diabetic encephalopathy by regulating the IGF-1Rsignaling pathway.

Revisiting the IGF-1R Signaling Pathway in Myeloproliferative Neoplasms: Quantification of IGF-1 Receptor May be Useful in the Differential Diagnosis of Polycythemia

Endogenous erythroid colony formation in vitro is one of the important criteria for the diagnosis of polycythemia vera (PV). Extensive studies performed in the last decade suggest that IGF-1 plays a significant role in the erythropoiesis and endogenous colony formation in PV. Therefore, IGF-1R signal pathway is important in the pathogenesis of PV. We elected to revisit IGF-1R pathway by flow cytometry technique in PV and other myeolproliferative neoplasms (MPNs). 32 MPN patients (including 11 PV, 19 myelofibrosis (MF), 12 essential thrombocytopenia (ET), 8 secondary PV , and 17 age-matched normal controls were studied. Methods: 1) plasma IGF-1, IGFBP-1, IGFBP-3 were assayed by ELISA(R&D Systems, Minneapolis, MN) ; 2) quantification of IGF-1R . Peripheral blood mononuclear cells (MNC) harvested from Ficoll-Paque separation were stained with phycoerythrin conjugated antibody against IGF-1 receptor (R&D Systems), and assayed by flow cytometry using FACS Calibur system (BD Biosciences, San Jose, CA; 3) quantification of IGF-1R phosphoration (pIGF-1R) after IGF-1 stimulation. MNC cells were suspended in serum-free α-MEM medium for 2 hours, then starved cells were treated with or without 10 nM IGF-1 for 3 min and assayed for pIGF-1R by flow cytometry using Alexa Fluor 647 conjugated antibody against phosphorylated IGF-1 receptor (BD Biosciences); 4) Interferon alpha (IFNα) Treatment. IFN-α (Schering Corporation, Kenilworth, NJ) was added to the cell culture at 100 unit per ml. Cells were incubated with IFN-α for either 2 hours or 3 days and then collected for further pIGF-1R analysis. The results showed 1) No difference in plasma IGF-1 levels in MPN and controls; IGFBP-1 and IGFBP-3 were significantly elevated in MPN than controls but the change of IGFBP-3 in MF patients was not significant. 2) the PV group had significantly elevated IGF-1R expression than secondary PV (Fig 1). Mean ± SE (MFI expression) were 529 ± 84 and 90 ± 30 in PV versus secondary PV, respectively (p=0.004). 3) The untreated PV group had significantly higher IGF-1R than MF, ET, and controls. MF and ET were not different from controls, but 8/19 (43%) in MF and 6/12 (50%) in ET have elevated IGF-1R than controls. 4) No difference in IGF-1R expression in Jak2 (+) versus Jak2 (-) in MPN patients. Mean ± SE (MFI) were 293.2 ± 62.1 and 164.8 ± 47.7 in JAK2(+) versus JAK2 (-) respectively (p=NS). 5) Preliminary studies showed PV has a significant elevated pIGF-1R than controls in unstimulated PB CD34+ cells, but not in MNC cells. 6) IFN-α decreased IGF-1R expression and pIGF-IR about 10% in the PV group.Conclusions: 1) IGF1R signal pathway is more active in PV than MF, ET and controls. 2) Quantification of IGF-1R expression by flow cytometry may be helpful in differential diagnosis in primary versus secondary PV. 3) IGF-1R expression is not correlated with JAK2 status. 4) IGF-1R phosphorylation is more elevated in unstimulated CD34+ cells of PV patients than in controls suggesting autonomous erythroid colony formation in PV may be associated with IGF-1R activation. 5) interferon-α has some inhibitory effects in IGF-1R expression and phosphorylation but is unlikely to be the main mechanism of its induced remission of JAK2 –mutant allele-burden effects. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

GALNT2 suppresses malignant phenotypes through IGF-1 receptor and predicts favorable prognosis in neuroblastoma.

Aberrant expression of the simple mucin-type carbohydrate antigens such as Tn antigen is associated with malignant transformation and cancer progression. N-acetylgalactosaminyltransferase 2 (GALNT2), one of the enzymes that mediate the initial step of mucin-type O-glycosylation, is responsible for forming Tn antigen. GALNT2 is expressed differentially in nervous tissues during mouse embryogenesis; however, the role of GALNT2 in neuroblastoma (NB) remains unclear. Here we showed that increased GALNT2 expression evaluated using immunohistochemistry in NB tumor tissues correlated well with the histological grade of differentiation as well as younger age at diagnosis, early clinical stage, primary tumor originated from the extra-adrenal site, favorable INPC histology, and MYCN non-amplification. Multivariate analysis showed that GALNT2 expression is an independent prognostic factor for better survival for NB patients. GALNT2 overexpression suppressed IGF-1-induced cell growth, migration, and invasion of NB cells, whereas GALNT2 knockdown enhanced these NB phenotypes. Mechanistic investigations demonstrated that GALNT2 overexpression modified O-glycans on IGF-1R, which suppressed IGF-1-triggered IGF-1R dimerization and subsequent downstream signaling events. Conversely, these properties were reversed by GALNT2 knockdown in NB cells. Our findings suggest that GALNT2 regulates malignant phenotypes of NB cells through the IGF-1R signaling pathway, suggesting a critical role for GALNT2 in the pathogenesis of NB.

Abstract 3389: Targeting SALL4 in lung cancer through a novel Cbl-b/IGF1R&amp;EGFR axis

Abstract Lung cancer is the leading cause of cancer deaths in the United States with an estimated &amp;gt;160,000 deaths and &amp;gt;200,000 newly diagnosed cases each year. Over the past 20 years, the survival rate for patients remains extremely poor (∼15% over 5 years). Discovery of novel pathway involved in the pathogenesis of the lung cancer can provide new therapeutic opportunities. Stem cell factor SALL4 has recently merged to be a diagnostic tool and therapeutic target for acute myeloid leukemia and liver cancer. However, very little is known on its role in lung cancer. In order to investigate the functional role of SALL4 in lung cancer tumorigenesis and progression, we first performed gene expression profile analysis and revealed that SALL4 expression level was significant higher in all types of non-small cell lung cancer samples compared to normal lung tissue control, which was validated by IHC. Furthermore, we performed loss of function study using multiple shRNAs. Our data showed that knockdown of SALL4 could induce dramatic cell growth arrest in multiple lung cell lines including large cell carcinoma H661 and adenocarcinoma H522, H292 and PC9, but not in HCC827 cells with none/low SALL4 level. In order to elucidate the downstream pathway of SALL4 in lung cancer, we first conducted gene expression microarray using SALL4 knockdown H661 cells and cells treated with scramble control vectors. Combination of one-way ANOVA analysis and pathway analysis using Pathway Interaction Database (PID) showed that both the EGFR and IGF1R signaling pathways were affected by SALL4 knockdown in H661 lung cancer cells. Using western blot, we further validated that SALL4 depletion could lead to a decrease in both EGFR and IGF1R protein expressions in lung cancer cells. However, we did not observe any changes at the mRNA level for these two receptors upon SALL4 depletion. This leads us to wonder whether SALL4 could affect these two molecules indirectly. It has been well established that receptor tyrosine kinase (RTK) including EGFR and IGF1R can be negatively regulated by Cbl RING ubiquitin ligases. Of interest, our microarray data also showed that loss of SALL4 led to a dramatic upregulation of Cbl-b, a member of Cbl RING ligases, which was further validated by using real-time RT-PCR. In addition, SALL4 downregulation also dramatically increased Cbl-b protein expression in these lung cancer cells. Therefore, we propose that SALL4 can indirectly positively affect the expression of EGFR and IGF1R proteins through Cbl-b. In summary, we have demonstrated that SALL4 expression is aberrantly elevated in non-small cell lung cancer cells. Furthermore our data suggested that SALL4 plays an essential role in lung cancer tumor growth and maintenance by affecting both EGFR and IGFR signaling pathways via regulating Cbl-b expression. Citation Format: Ailing Li, Wenbin Ou, Jonathan Fletcher, Kol Jia Yong, Henry Yang, Ross Soo, Daniel Tenen, Li Chai. Targeting SALL4 in lung cancer through a novel Cbl-b/IGF1R&amp;EGFR axis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3389. doi:10.1158/1538-7445.AM2014-3389

Randomized, controlled, multicenter, multinational phase 2 study of docetaxel (DCT) or AXL1717 treatment in patients with squamous cell carcinoma (SCC) or adenocarcinoma (AC) of non-small cell lung cancer (NSCLC).

8091 Background: AXL1717 (picropodophyllin) is small molecule that inhibits the IGF-1R signaling pathway as well as suppresses tumor cell division by arresting cells in mitosis through a non-IGF-1R dependent mechanism. Preclinical data have shown extensive anti-tumor effects includingcomplete regressionsin xenograft studies against a range of tumors. Methods: A total of 101 patients (99 treated, ITT population) with locally advanced or metastatic NSCLC (Stage IIIB or IV, SCC or AD) with 1-2 lines of previous treatmentwere randomized. Patients had ECOG PS 0–2 and a life expectancy ≥ 3 months. The patients were randomized to either AXL1717 or DCT as monotherapy, in a 3:2 ratio for each NSCLC subtype. AXL1717 was administrated as an oral suspension given twice daily ata dose of 400 mg (later changed to 300 mg) and DCT was administered at 75 mg/m2 on Day 1 of every 21-day cycle. The treatmentduration was 12 weeks. Results: The primary objective was to compare the rate of progression-free survival (PFS) at 12 ...

A phase 1, open-label, dose-escalation study of BIIB022 (anti-IGF-1R monoclonal antibody) in subjects with relapsed or refractory solid tumors

Summary Purpose The IGF-1R signaling pathway has been implicated in multiple cancers as important for cell survival, proliferation, invasion and metastasis. BIIB022 is a non-glycosylated human IgG4 monoclonal antibody (mAb) with specificity for IGF-1R. Unlike other anti-IGF1R antibodies, BIIB022 has no effector functions. Additionally, inhibition is via an allosteric rather than competitive mechanism, which further differentiates this antibody from others. We sought to determine the safety and tolerability of BIIB022 and determine the pharmacokinetic (PK) and pharmacodynamic (PD) profile of this antibody. Methods A multi-institutional phase I study evaluated the safety of escalating doses of BIIB022 given IV q3wk until progression or unacceptable toxicity in patients with advanced solid tumors. Five sequential BIIB022 dose cohorts were evaluated using a standard 3 + 3 dose-escalation design (1.5, 5. 10, 20, 30 mg/kg); 10 additional patients were treated at the recommended phase 2 dose. Results 34 patients were treated. Toxicities were manageable and mostly low grade; grade 3–4 hyperglycemia was not observed. No RECIST responses were observed, although three patients had metabolic responses associated with prolonged stable disease. The PK of BIIB022 was nearly linear in the dose range from 10 to 30 mg/kg, with some nonlinearity at lower doses (1.5–5.0 mg/kg), likely due to target-mediated drug disposition of BIIB022 at low serum concentrations. PD analyses showed decrease in IGF-1R levels on leucocytes, with stable serum values of IGF-1 and IGF-2. Conclusions BIIB022 can be safely given at 30 mg/kg IV every 3 weeks with preliminary evidence of biological activity in selected patients.

Ezrin expression and cell survival regulation in colorectal cancer

Colorectal cancer (CRC) is the second largest cause of cancer deaths in the United States. A key barrier that prevents better outcomes for this type of cancer as well as other solid tumors is the lack of effective therapies against the metastatic disease. Thus there is an urgent need to fill this gap in cancer therapy. We utilized a 2D-DIGE proteomics approach to identify and characterize proteins that are differentially regulated between primary colon tumor and liver metastatic deposits of the IGF1R-dependent GEO human CRC xenograft, orthotopically implanted in athymic nude mice that may serve as potential therapeutic targets against CRC metastasis. We observed increased expression of ezrin in liver metastasis in comparison to the primary colonic tumor. Increased ezrin expression was further confirmed by western blot and microarray analyses. Ezrin, a cytoskeletal protein belonging to Ezrin–Radixin–Moesin (ERM) family plays important roles in cell motility, invasion and metastasis. However, its exact function in colorectal cancer is not well characterized. Establishment of advanced GEO cell lines with enhanced liver-metastasizing ability showed a significant increase in ezrin expression in liver metastasis. Increased phosphorylation of ezrin at the T567 site (termed here as p-ezrin T567) was observed in liver metastasis. IHC studies of human CRC patient specimens showed an increased expression of p-ezrin T567 in liver metastasis compared to the primary tumors of the same patient. Ezrin modulation by siRNA, inhibitors and T567A/D point mutations significantly downregulated inhibitors of apoptosis (IAP) proteins XIAP and survivin that have been linked to increased aberrant cell survival and metastasis and increased cell death. Inhibition of the IGF1R signaling pathway by humanized recombinant IGF1R monoclonal antibody MK-0646 in athymic mouse subcutaneous xenografts resulted in inhibition of p-ezrin T567 indicating ezrin signaling is downstream of the IGF1R signaling pathway. We identified increased expression of p-ezrin T567 in CRC liver metastasis in both orthotopically implanted GEO tumors as well as human patient specimens. We report for the first time that p-ezrin T567 is downstream of the IGF1R signaling and demonstrate that ezrin regulates cell survival through survivin/XIAP modulation.

Formononetin induces the mitochondrial apoptosis pathway in prostate cancer cells via downregulation of the IGF-1/IGF-1R signaling pathway

Context: Formononetin, an isoflavone, can inhibit the proliferation of cancer cells, including those of the prostate. However, its antitumor mechanism remains unclear.Aim: To investigate whether the insulin-like growth factor 1 (IGF-1)/insulin-like growth factor 1 receptor (IGF-1 R) signaling pathway mediates the formononetin antitumor effect on prostate cancer cells.Materials and methods: The viability of PC-3 cells was measured by MTT assay 48 h after formononetin treatment (25, 50 and 100 μM). Formononetin-induced cell apoptosis was measured by Hoechst 33258 staining and flow cytometry. Expression of Bax mRNA was detected by real-time PCR, and the expression levels of Bax and IGF-1 R proteins were detected by western blots.Results: At concentrations >12.5 μM, formononetin significantly inhibited the proliferation of human prostate cancer cells. Formononetin increased Bax mRNA and protein expression levels and decreased the expression levels of pIGF-1 R protein in a dose-dependent manner.Conclusion: High concentrations of formononetin-induced apoptosis in androgen-independent prostate cancer cells through inhibition of the IGF-1/IGF-1 R pathway.

Maternal Dietary Restriction During the Periconceptional Period in Normal-Weight or Obese Ewes Results in Adrenocortical Hypertrophy, an Up-Regulation of the JAK/STAT and Down-Regulation of the IGF1R Signaling Pathways in the Adrenal of the Postnatal Lamb

Maternal dietary restriction during the periconceptional period results in an increase in adrenal growth and in the cortisol stress response in the offspring. The intraadrenal mechanisms that result in the programming of these changes are not clear. Activation of the IGF and the signal transducer and activator of transcription (STAT)/suppressors of cytokine signaling (SOCS) pathways regulate adrenal growth. We have used an embryo transfer model in sheep to investigate the impact of exposure to either dietary restriction in normal or obese mothers or to maternal obesity during the periconceptional period on adrenal growth and function in the offspring. We assessed the adrenal abundance of key signaling molecules in the IGF-I and Janus kinase/STAT/SOCS pathways including IGF-I receptor, IGF-II receptor, Akt, mammalian target of rapamycin, ribosomal protein S6, eukaryotic translation initiation factor 4E-binding protein 1, eukaryotic translation initiation factor 4E, STAT1, STAT3, STAT5, SOCS1, and SOCS3 in female and male postnatal lambs. Maternal dietary restriction in the periconceptional period resulted in the hypertrophy of the adrenocortical cells in the zona fasciculata-reticularis and an up-regulation in STAT1, phospho-STAT1, and phospho-STAT3 (Ser727) abundance and a down-regulation in IGF-I receptor, Akt, and phospho-Akt abundance in the adrenal cortex of the postnatal lamb. These studies highlight that weight loss around the time of conception, independent of the starting maternal body weight, results in the activation of the adrenal Janus kinase/STAT pathway and adrenocortical hypertrophy. Thus, signals of adversity around the time of conception have a long-term impact on the mechanisms that regulate adrenocortical growth.