Potential of proteomics towards the investigation of the IGF-independent actions of IGFBP-3

Construction and validation of a novel IGFBP3-related signature to predict prognosis and therapeutic decision making for Hepatocellular Carcinoma

Background

IGFBP3 plays a pivotal role in carcinogenesis by being anomalously expressed in some malignancies. However, the clinical value of IGFBP3 and the role of IGFBP3-related signature in HCC remain unclear.

Methods

Multiple bioinformatics methods were used to determine the expression and diagnostic values of IGFBP3. The expression level of IGFBP3 was validated by RT-qPCR and IHC. A IGFBP3-related risk score (IGRS) was built via correlation analysis and LASSO Cox regression analysis. Further analyses, including functional enrichment, immune status of risk groups were analyzed, and the role of IGRS in guiding clinical treatment was also evaluated.

Results

IGFBP3 expression was significantly downregulated in HCC. IGFBP3 expression correlated with multiple clinicopathological characteristics and demonstrated a powerful diagnostic capability for HCC. In addition, a novel IGRS signature was developed in TCGA, which exhibited good performance for prognosis prediction and its role was further validated in GSE14520. In TCGA and GSE14520, Cox analysis also confirmed that the IGRS could serve as an independent prognostic factor for HCC. Moreover, a nomogram with good accuracy for predicting the survival of HCC was further formulated. Additionally, enrichment analysis showed that the high-IGRS group was enriched in cancer-related pathways and immune-related pathways. Additionally, patients with high IGRS exhibited an immunosuppressive phenotype. Therefore, patients with low IGRS scores may benefit from immunotherapy.

Conclusions

IGFBP3 can act as a new diagnostic factor for HCC. IGRS signature represents a valuable predictive tool in the prognosis prediction and therapeutic decision making for Hepatocellular Carcinoma.

Insulin-like growth factor binding protein-3 induces senescence by inhibiting telomerase activity in MCF-7 breast cancer cells

Insulin-like growth factor binding protein-3 (IGFBP-3) has been known to inhibit cell proliferation and exert tumor-suppressing effects depending on the cell type. In this study, we aimed to show that IGFBP-3 induces cellular senescence via suppression of the telomerase activity, thereby inhibiting MCF-7 breast cancer cell proliferation. We found that the induction of IGFBP-3 in MCF-7 cells enhanced the loss of cell viability. Flow cytometry revealed a higher percentage of non-cycling cells among IGFBP-3-expressing cells than among controls. IGFBP-3 induction also resulted in morphological alterations, such as a flattened cytoplasm and increased granularity, suggesting that IGFBP-3 induces a senescence-like phenotype. The percentage of IGFBP-3 expressing cells with senescence-associated β-galactosidase activity was 3.4 times higher than control cells. Telomeric repeat amplification and real-time PCR showed that IGFBP-3 decreased telomerase activity by reducing the levels of the RNA component (hTR) and catalytic protein component with reverse transcriptase activity (hTERT) of telomerase in a dose-dependent manner. These results suggest that IGFBP-3 is a negative regulator of MCF-7 breast cancer cell growth by inducing senescence through telomerase suppression.

Low expression levels of insulin-like growth factor binding protein-3 are correlated with poor prognosis for patients with hepatocellular carcinoma

Insulin-like growth factor binding protein-3 (IGFBP-3) has previously been identified as a putative tumor suppressor gene. The present study investigated the clinical and prognostic significance of IGFBP-3 expression levels in patients with hepatocellular carcinoma (HCC). Immunohistochemistry (IHC) probing for IGFBP-3 was performed on paraffin-embedded tissue samples obtained from 120 patients with HCC, including tissue samples from 120 primary cancer sites and 50 matched adjacent non-malignant sites. Receiver-operator curve (ROC) analysis was used to determine the cut-off scores for the presence of IGFBP-3-positive tumor cells and to estimate the survival time of the patients. The threshold for marking the positive expression of IGFBP-3 was 65%, based on the area under the ROC. Positive expression of IGFBP-3 was observed in 65/120 (54.2%) of the HCC tissues, and in 36/50 (72%) of the adjacent non-malignant liver tissues. Low levels of IGFBP-3 expression were correlated with tumor size (P=0.003), tumor multiplicity (P=0.044), node (P=0.008), metastasis (P=0.001) and clinical stage (P=0.001), as well as reduced survival time (P=0.015). Using univariate survival analysis, a significant direct correlation between high and low IGFBP-3 expression levels, and patient survival time (mean survival time high IGFBP-3, 39.4 vs. low IGFBP-3, 18.7 months) was identified. Kaplan-Meier analysis demonstrated that IGFBP-3 expression levels and patients survival time were significantly correlated (P<0.001). Multivariate analysis revealed IGFBP-3 expression to be an independent parameter (P=0.003). Therefore, low levels of IGFBP-3 expression are associated with advance clinicopathological classification and may be a predictor of poor survival in patients with HCC. Furthermore, these findings suggest that IGFBP-3 may serve as an independent molecular marker for the evaluation of prognosis in patients with HCC.

Thyroid diseases in patients with acromegaly

Acromegaly often involves the presence of different pathologies of the thyroid gland. Long-lasting stimulation of the follicular epithelium by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) can cause disorders in thyroid function, an increase in its mass and the development of goitre. Acromegalic patients present most frequently with non-toxic multinodular goitre. Nodules are more prevalent in patients with active acromegaly. It has been suggested that then thyroid size increases and it can be reduced through treatment with somatostatin analogues. The relationship between thyroid volume and the level of IGF-1 and the duration of the disease is unclear. Each acromegalic patient requires a hormonal and imaging evaluation of the thyroid when the diagnosis is made, and an accurate evaluation during further observation and treatment. Although the data concerning the co-occurrence of acromegaly and thyroid cancer still remain controversial, it is particularly important to diagnose the patient early and to rule out thyroid cancer.

A protective role of sulforaphane on alveolar epithelial cells exposed to cigarette smoke extract

BACKGROUND

Sulforaphane (SFN) is an excellent antioxidant agent, few of the studies focus on the possible protective role of SFN from cigarette smoke-induced injury on alveolar epithelial cells.

OBJECTIVES

the aim of the study is to observe the possible protective role of SFN, as well as the function of insulin-like growth factor binding protein-3 (IGFBP-3) in the process.

METHODS

MTT assay was used to evaluate cell viability after cigarette smoke extract (CSE) and/or SFN exposure, cell cycle was analyzed using flow cytometry, intracellular reactive oxygen species (ROS) level was detected by staining with fluorescent indicator 2', 7'-dichlorofluorescin diacetate (DCFH-DA), finally both real-time quantitative RT-PCR and western blot were employed to observe mRNA and protein levels of IGFBP-3.

RESULTS

SFN could restore the viability of A549 cells, attenuate G1 block of the cell cycle, and significantly reduce the proportion of sub-G1 cells; at the same time, CSE-induced accumulation of intracellular ROS was decreased by SFN. Interestingly, high expression of IGFBP-3 was found at both transcriptional and translational levels, however by pre-incubation with SFN, the expression of IGFBP-3 was not stimulated by CSE exposure.

CONCLUSIONS

SFN can antagonize CSE-induced growth arrest of alveolar epithelial cells and IGFBP-3 probably plays an important role in the process.

Targeting the IGF1 axis in cancer proliferation

The IGF network of ligands, cell-surface receptors and IGF-binding proteins has important roles at multiple levels, including the cellular, organ and organism levels. The IGF system mediates growth, differentiation and developmental processes, and is also involved in various metabolic activities. Dysregulation of IGF system expression and action is linked to diverse pathologies, ranging from growth deficits to cancer development. Targeting of the IGF axis emerged in recent years as a promising therapeutic approach in conditions in which the IGF system is involved. Specific IGF1 receptor (IGF1R) targeting, in particular, produced the best experimental and clinical results so far, and generated significant optimism in the field. This review provides a basic analysis of the role of the IGF1R in cancer biology and explores the functional interactions between the IGF signaling pathways and various cancer genes (e.g., oncogenes, tumor suppressors). In addition, we review a number of specific malignancies in which the IGF system is involved and summarize recent data on preclinical and clinical studies employing IGF1R-targeted modalities.

Expression of components of the IGF axis in childhood acute myelogenous leukemia

BACKGROUND

Insulin-like growth factor (IGF) system as regulator for cellular proliferation is of particular interest in search for new prognostic approaches in cancer treatment.

PROCEDURE

We analyzed the mRNA expression profile of IGF-I, -II, and IGFBP-2, -3 in 50 children with previously untreated AML (mean age 10.8 +/- 4.8 years; patients in CCR n = 20, patients with relapse during later course of disease n = 15). MNC samples from peripheral blood as well as bone marrow of healthy donors were used as controls.

RESULTS

IGFBP-2 expression was significantly higher in AML cells than in healthy cells of peripheral MNC (P < 0.001) and of bone marrow cells (P < 0.01). Conversely, AML cells showed significantly lower IGFBP-3 and IGF-I gene expression compared to controls (P = 0.02; P < 0.001). Patients with relapse (median +/- range: 0.0929 +/- 0.049) during later course of disease demonstrated higher IGFBP-2 expression compared to patients in CCR (0.0121 +/- 0.047; P = 0.06) at time of diagnosis. A multivariate analysis identified the IGFBP-2 mRNA expression as an independent factor for the prediction of relapse. Furthermore, the probability of relapse-free survival (RFS) in patients with IGFBP-2 mRNA level >0.1000 was 28%; whereas, the probability of RFS in patients with IGFBP-2 mRNA level <0.1000 was 62% (P = 0.04, log-rank test). No prognostic influence could be found for the other investigated genes.

CONCLUSIONS

Results identified different expressions of IGF components between normal and AML cells. Patients with IGFBP-2 mRNA levels up to 0.1000 (relative to KG1 cell line) more likely developed a relapse. Identification of these patients at diagnosis may allow more individualized treatment.

Elevated serum insulin-like growth factor binding protein-2 is associated with a high relapse risk after hematopoietic stem cell transplantation in childhood AML

Insulin-like growth factor binding protein (IGFBP)-2 has mitogenic effects in normal and neoplastic cells. The purpose of this study is to examine the diagnostic and prognostic significance of elevated IGFBP-2 levels in children with AML after hematopoietic stem cell transplantation (HSCT) at relapse and continuous complete remission (CCR). In 27 children with AML (mean age 13.6+/-5.3 years; patients in remission n=15 with relapse n=12) serum parameters of IGFBP-2, IGFBP-3, IGF-I and IGF-II were analyzed up to 18 months after HSCT by RIA. AML-patients with evidence of relapse demonstrated a continuous increase of IGFBP-2 levels during the follow-up. At day 100 after HSCT, IGFBP-2 concentrations were significantly higher in patients with relapse than in children without relapse (7.4+/-4.0 standard deviation score (SDS) vs 3.9+/-1.7 SDS; P=0.01). Serum IGFBP-2 was identified as an independent factor for the prediction of relapse. Furthermore, the probability of relapse-free survival (RFS) in patients with IGFBP-2 >4.5 SDS at day 100 after HSCT was 31% compared to patients with IGFBP-2 <4.5 SDS was 72% (P=0.004). Patients with IGFBP-2 concentration up to 4.5 SDS more likely developed a relapse and had a poorer outcome. Identification of these patients allows a more individualized and aggressive adjuvant treatment and follow-up.