Update of IGF-1 receptor inhibitor (ganitumab, dalotuzumab, cixutumumab, teprotumumab and figitumumab) effects on cancer therapy

Inhibitor of IGF1 receptor alleviates the inflammation process in the diabetic kidney mouse model without activating SOCS2

Objective

To explore the anti-inflammatory mechanism of IGF1R inhibitor in diabetic nephropathy.

Methods

C57/BL6 mice were reared with high-fat diet for 8 weeks, then were injected 30 mg/kg streptozotocin intraperitoneally to induce type 2 diabetes. After 8 weeks, the type 2 diabetes nephropathy model was successfully set up the different drugs were administrated to mice with diabetes (insulin 1-2 U/day, benazepril 10 mg/kg per day intragastrically, IGF-1R inhibitor 30 mg/kg per day intragastrically). After 8 weeks drugs administration, all mice were collected the kidney tissue, measured levels of inflammatory factor (F4/80, TLR4and CD68) and fibrosis markers(αSMA, E-cadherin and SR) using immunohistochemistry and in situ hybridization.

Results

The type 2 diabetes nephropathy model was built successfully, which along with increased urinary protein excretion rate and increased inflammatory infiltration, and the correlation was characterized by increased CD68⁺, F4/80⁺ cells and increased TLR4, αSMA, SR expression. IGF-1R inhibitors reversed this changes, but benazepril and insulin were without significant changes. The insulin decreased the expression level of IGF-1, and increased the levels of suppressor of cytokine signaling 2 (SOCS2). Benazepril and IGF-1R inhibitor were no significant changes like insulin.

Conclusion

Inhibition of IGF1R was a more effective choice for inflammation treatment than Ben or Ins in diabetic kidney disease (DKD). The IGF1R inhibitor blocked pathological changes induced by the over-expression of IGF1 in DKD without up-regulating SOCS2 protein levels.

Challenges in Orphan Drug Development: Identification of Effective Therapy for Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease, is a process in which orbital connective tissues and extraocular muscles undergo inflammation and remodeling. The condition seems to result from autoimmune responses to antigens shared by the thyroid and orbit. The thyrotropin receptor (TSHR), expressed at low levels in orbital tissues, is a leading candidate antigen. Recent evidence suggests that another protein, the insulin-like growth factor-I receptor (IGF-IR), is overexpressed in TAO, and antibodies against IGF-IR have been detected in patients with the disease. Furthermore, TSHR and IGF-IR form a physical and functional complex, and signaling initiated at TSHR requires IGF-IR activity. Identification of therapy for this rare disease has proven challenging and currently relies on nonspecific and inadequate agents, thus representing an important unmet need. A recently completed therapeutic trial suggests that inhibiting IGF-IR activity with a monoclonal antibody may be an effective and safe treatment for active TAO.

IGF1 receptor and thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a vexing and poorly understood autoimmune process involving the upper face and tissues surrounding the eyes. In TAO, the orbit can become inflamed and undergo substantial remodeling that is disfiguring and can lead to loss of vision. There are currently no approved medical therapies for TAO, the consequence of its uncertain pathogenic nature. It usually presents as a component of the syndrome known as Graves' disease where loss of immune tolerance to the thyrotropin receptor (TSHR) results in the generation of activating antibodies against that protein and hyperthyroidism. The role for TSHR and these antibodies in the development of TAO is considerably less well established. We have reported over the past 2 decades evidence that the insulin-like growth factorI receptor (IGF1R) may also participate in the pathogenesis of TAO. Activating antibodies against IGF1R have been detected in patients with GD. The actions of these antibodies initiate signaling in orbital fibroblasts from patients with the disease. Further, we have identified a functional and physical interaction between TSHR and IGF1R. Importantly, it appears that signaling initiated from either receptor can be attenuated by inhibiting the activity of IGF1R. These findings underpin the rationale for therapeutically targeting IGF1R in active TAO. A recently completed therapeutic trial of teprotumumab, a human IGF1R inhibiting antibody, in patients with moderate to severe, active TAO, indicates the potential effectiveness and safety of the drug. It is possible that other autoimmune diseases might also benefit from this treatment strategy.

IGF system in sarcomas: a crucial pathway with many unknowns to exploit for therapy

The insulin-like growth factor (IGF) system has gained substantial interest due to its involvement in regulating cell proliferation, differentiation and survival during anoikis and after conventional and targeted therapies. However, results from clinical trials have been largely disappointing, with only a few but notable exceptions, such as trials targeting sarcomas, especially Ewing sarcoma. This review highlights key studies focusing on IGF signaling in sarcomas, specifically studies underscoring the properties that make this system an attractive therapeutic target and identifies new relationships that may be exploited. This review discusses the potential roles of IGF2 mRNA-binding proteins (IGF2BPs), discoidin domain receptors (DDRs) and metalloproteinase pregnancy-associated plasma protein-A (PAPP-A) in regulating the IGF system. Deeper investigation of these novel regulators of the IGF system may help us to further elucidate the spatial and temporal control of the IGF axis, as understanding the control of this axis is essential for future clinical studies.

Insulin-Like Growth Factor-1 Signaling in Lung Development and Inflammatory Lung Diseases

Insulin-like growth factor-1 (IGF-1) was firstly identified as a hormone that mediates the biological effects of growth hormone. Accumulating data have indicated the role of IGF-1 signaling pathway in lung development and diseases such as congenital disorders, cancers, inflammation, and fibrosis. IGF-1 signaling modulates the development and differentiation of many types of lung cells, including airway basal cells, club cells, alveolar epithelial cells, and fibroblasts. IGF-1 signaling deficiency results in alveolar hyperplasia in humans and disrupted lung architecture in animal models. The components of IGF-1 signaling pathways are potentiated as biomarkers as they are dysregulated locally or systemically in lung diseases, whereas data may be inconsistent or even paradoxical among different studies. The usage of IGF-1-based therapeutic agents urges for more researches in developmental disorders and inflammatory lung diseases, as the majority of current data are collected from limited number of animal experiments and are generally less exuberant than those in lung cancer. Elucidation of these questions by further bench-to-bedside researches may provide us with rational clinical diagnostic approaches and agents concerning IGF-1 signaling in lung diseases.

β-catenin/TCF activity regulates IGF-1R tyrosine kinase inhibitor sensitivity in colon cancer

The availability of large-scale drug screening data on cell line panels provides a unique opportunity to identify predictive biomarkers for targeted drug efficacy. Analysis of diverse drug data on ~990 cancer cell lines revealed enhanced sensitivity of insulin-like growth factor 1 receptor/ Insulin Receptor (IGF-1R/IR) tyrosine kinase inhibitors (TKIs) in colon cancer cells. Interestingly, β-catenin/TCF(T cell factor)-responsive promoter activity exhibited a significant positive association with IGF-1R/IR TKI response, while the mutational status of direct upstream genes, such as CTNNB1 and APC, was not significantly associated with the response. The β-catenin/TCF activity high cell lines express components of IGF-1R/IR signaling more than the low cell lines explaining their enhanced sensitivity against IGF-1R/IR TKI. Reinforcing β-catenin/TCF responsive promoter activity by introducing CTNNB1 gain-of-function mutations into IGF-1R/IR TKI-resistant cells increased the expression and activity of IGF-1R/IR signaling components and also sensitized the cells to IGF-1R/IR TKIs in vitro and in vivo. Analysis of TCGA data revealed that the stronger β-catenin/TCF responsive promoter activity was associated with higher IGF-1R and IGF2 transcription in human colon cancer specimens as well. Collectively, compared to the mutational status of upstream genes, β-catenin/TCF responsive promoter activity has potential to be a stronger predictive positive biomarker for IGF-1R/IR TKI responses in colon cancer cells. The present study highlights the potential of transcriptional activity as therapeutic biomarkers for targeted therapies, overcoming the limited ability of upstream genetic mutations to predict responses.

Epithelial-Mesenchymal Transition (EMT) and Prostate Cancer

Typically the normal epithelial cells are a single layer, held tightly by adherent proteins that prevent the mobilization of the cells from the monolayer sheet. During prostate cancer progression, the epithelial cells can undergo epithelial-mesenchymal transition or EMT, characterized by morphological changes in their phenotype from cuboidal to spindle-shaped. This is associated with biochemical changes in which epithelial cell markers such as E-cadherin and occludins are down-regulated, which leads to loss of cell-cell adhesion, while mesenchymal markers such as vimentin and N-cadherin are up-regulated, thereby allowing the cells to migrate or metastasize to different organs. The EMT transition can be regulated directly and indirectly by multiple molecular mechanisms including growth factors and cytokines such as transforming growth factor-beta (TGF-β), epidermal growth factor (EGF) and insulin-like growth factor (IGF), and signaling pathways such as mitogen-activated protein kinase (MAPK) and Phosphatidylinositol 3-Kinase (PI3K). This signaling subsequently induces expression of various transcription factors like Snail, Twist, Zeb1/2, that are also known as master regulators of EMT. Various markers associated with EMT have been reported in prostate cancer patient tissue as well as a possible association with health disparities. There has been consideration to therapeutically target EMT in prostate cancer patients by targeting the EMT signaling pathways.

Treatment for the endocrine resistant breast cancer: Current options and future perspectives

Endocrine resistance remains a challenge and an unmet need for managing hormone receptor-positive breast cancer. The mechanisms of endocrine resistance are multifaceted and are likely to evolve over time following various single or combination therapies. The purpose of this review article is to provide general understanding of molecular basis of endocrine resistance of breast cancer and to offer comprehensive review on current treatment options and potential new treatment strategies for endocrine resistant breast cancers. Last but not the least, we discuss current challenges and future directions for management of endocrine resistant breast cancers.

Autocrine mechanisms of cancer chemoresistance

An ever-increasing number of studies highlight the role of cancer secretome in the modification of tumour microenvironment and in the acquisition of cancer cell resistance to therapeutic drugs. The knowledge of the mechanisms underlying the relationship between cancer cell-secreted factors and chemoresistance is becoming fundamental for the identification of novel anticancer therapeutic strategies overcoming drug resistance and novel prognostic secreted biomarkers. In this review, we summarize the novel findings concerning the regulation of secreted molecules by cancer cells compromising drug sensitivity. In particular, we highlight data from available literature describing the involvement of cancer cell-secreted molecules determining chemoresistance in an autocrine manner, including: i) growth factors; ii) glycoproteins; iii) inflammatory cytokines; iv) enzymes and chaperones; and v) tumor-derived exosomes.