Insulin-like growth factor-II as a prognostic factor in pulmonary adenocarcinoma

DNA Methylation Readers and Cancer: Mechanistic and Therapeutic Applications

DNA methylation is a major epigenetic process that regulates chromatin structure which causes transcriptional activation or repression of genes in a context-dependent manner. In general, DNA methylation takes place when methyl groups are added to the appropriate bases on the genome by the action of "writer" molecules known as DNA methyltransferases. How these methylation marks are read and interpreted into different functionalities represents one of the main mechanisms through which the genes are switched "ON" or "OFF" and typically involves different types of "reader" proteins that can recognize and bind to the methylated regions. A tightly balanced regulation exists between the "writers" and "readers" in order to mediate normal cellular functions. However, alterations in normal methylation pattern is a typical hallmark of cancer which alters the way methylation marks are written, read and interpreted in different disease states. This unique characteristic of DNA methylation "readers" has identified them as attractive therapeutic targets. In this review, we describe the current state of knowledge on the different classes of DNA methylation "readers" identified thus far along with their normal biological functions, describe how they are dysregulated in cancer, and discuss the various anti-cancer therapies that are currently being developed and evaluated for targeting these proteins.

Insulin-like growth factor (IGF) axis in cancerogenesis

Determination of the role of insulin-like growth factor (IGF) family components in carcinogenesis of several human tumors is based on numerous epidemiological and pre-clinical studies, experiments in vivo and in vitro and on attempts at application of drugs affecting the IGF axis. Investigative hypotheses in original studies were based on biological functions manifested by the entire family of IGF (ligands, receptors, linking proteins, adaptor molecules). In the context of carcinogenesis the most important functions of IGF family involve intensification of proliferation and inhibition of cell apoptosis and effect on cell transformation through synthesis of several regulatory proteins. IGF axis controls survival and influences on metastases of cells. Interactions of IGF axis components may be of a direct or indirect nature. The direct effects are linked to activation of PI3K/Akt signaling pathway, in which the initiating role is first of all played by IGF-1 and IGF-1R. Activity of this signaling pathway leads to an increased mitogenesis, cell cycle progression, and protection against different apoptotic stresses. Indirect effects of the axis depend on interactions between IGF and other molecules important for cancer etiology (e.g. sex hormones, products of suppressor genes, viruses, and other GFs) and the style of life (nutrition, physical activity). From the clinical point of view, components of IGF system are first of all considered as diagnostic serous and/or tissue biomarkers of a given cancer, prognostic factors and attractive target of modern anti-tumor therapies. Several mechanisms in which IGF system components act in the process of carcinogenesis need to be clarified, mainly due to multifactorial etiology of the neoplasms. Pin-pointing of the role played in carcinogenesis by any single signaling pathway remains particularly difficult. The aim of this review is to summarize the current data of several epidemiological studies, experiments in vitro and on animal models, to increase our understanding of the complex role of IGF family components in the most common human cancers.

Activity of dalotuzumab, a selective anti-IGF1R antibody, in combination with erlotinib in unselected patients with Non-small-cell lung cancer: a phase I/II randomized trial

Background

We investigated the safety and antitumor activity of dalotuzumab, a selective anti-insulin growth factor 1 receptor monoclonal antibody (IGF1R MoAb), plus erlotinib in a sequential phase I/II trial in unselected patients with refractory advanced non-small-cell lung cancer (NSCLC).The phase I trial determined the recommended dose and safety of erlotinib plus dalotuzumab at 5 mg/kg or 10 mg/kg weekly in 20 patients. The phase II trial compared outcomes to erlotinib alone and erlotinib plus dalotuzumab at the mg/kg established in the phase I trial.

Results

Erlotinib at 150 mg plus dalotuzumab at 10 mg/kg was safe. The phase II trial included 37 patients in the erlotinib arm and 38 patients in the erlotinib plus dalotuzumab arm. Progression-free survival was 1.6 versus 2.5 months, overall survival was 10.2 and 6.6 months, and the objective response rate was 7.9% and 2.7%, respectively, with no significant differences between the two arms. Grade 3-5 adverse events occurred in 11 (28.9%) versus 13 (35.1%) patients, respectively. The most frequent adverse events were asthenia (36.8% vs. 37.8%), dehydration (5.3% vs. 2.7%), diarrhea (71% vs. 81.1%), hyperglycemia (13.1% vs.18.9%), and skin-related toxicities (92.1% vs. 86.4%).

Conclusion

The addition of dalotuzumab to erlotinib did not improve efficacy outcome in patients with refractory advanced NSCLC.

Preoperative insulin-like growth factor-binding protein-3 (IGFBP-3) blood level predicts gleason sum upgrading

BACKGROUND

About 43% of men with low Gleason grade prostate cancer (PCa) at biopsy will be finally diagnosed with high-grade PCa at radical prostatectomy (RP). Gleason sum at RP is a good indicator of biochemical recurrence and poor clinical outcome. Therefore, there is a need to improve clinical evaluation of PCa aggressiveness in order to choice appropriate treatment. To this aim an easy-available tool is represented by circulating biomarkers. Among these, the best candidates are some molecules involved in PCa pathogenesis such as IGFBP-2 and IGFBP-3, IL-6, and its soluble receptor (SIL-6R).

METHODS

In this study, we evaluated the ability of preoperative IGFBP-2, IGFBP-3, IL-6, and SIL-6R serum levels to predict Gleason score upgrade in 52 PCa patients.

RESULTS

We found that IGFBP-3 median levels were significantly lower in patients who showed Gleason upgrading from biopsy to RP (P = 0.024). We also found an association between biopsy T-stage and Gleason Upgrade (P = 0.011). Using multivariate logistic regression model, we demonstrated that the association of IGFBP-3 serum levels together with biopsy T-stage and biopsy Gleason score was useful to calculate a prognostic risk score. ROC curve analysis of risk score showed a good ability to predict GSU (AUC = 0.81; 95% CI 0.69-0.93).

CONCLUSIONS

Our results suggest that preoperative IGFBP-3 circulating levels determination may be useful to predict Gleason score upgrading alone and/or in combination with biopsy T-stage and biopsy Gleason score.

IMP3 expression is correlated with histologic grade of lung adenocarcinoma

Insulin-like growth factor II mRNA binding protein 3 is an oncofetal protein that is expressed in multiple malignancies. This study aimed to determine the correlation of insulin-like growth factor II mRNA binding protein 3 expression with histologic grade of lung adenocarcinoma. Eighty-nine cases, including 11 atypical adenomatous hyperplasias, 10 pure bronchioloalveolar carcinomas, 36 well-differentiated adenocarcinomas and 41 moderately or poorly differentiated adenocarcinomas, were immunohistochemically studied using a monoclonal antibody against insulin-like growth factor II mRNA binding protein 3. Twenty-nine (70.7%) of 41 moderately to poorly differentiated adenocarcinomas were positive for insulin-like growth factor II mRNA binding protein 3, with 26 (89.7%) tumors demonstrating either a strong staining or staining in greater than 30% of tumor cells. Four (40.0%) of 10 bronchioloalveolar carcinomas and 13 (36.1%) of 36 well-differentiated adenocarcinomas exhibited insulin-like growth factor II mRNA binding protein 3 positivity with a variable degree and percentage of tumor cells staining. When bronchioloalveolar carcinomas were present in a pure form or as a component of adenocarcinomas, positive insulin-like growth factor II mRNA binding protein 3 staining was always patchy, with less than 20% of tumor cells stained. Overall, the frequency of positive insulin-like growth factor II mRNA binding protein 3 staining was lower in bronchioloalveolar carcinomas and well-differentiated adenocarcinomas compared to moderately/poorly differentiated adenocarcinomas (P < .01). No insulin-like growth factor II mRNA binding protein 3 signal was detected in any case of atypical adenomatous hyperplasia. These findings show that insulin-like growth factor II mRNA binding protein 3 is strongly and diffusely expressed in a large proportion of moderately/poorly differentiated lung adenocarcinomas, in particular in the solid component of mixed subtype adenocarcinomas, less frequently expressed in well-differentiated adenocarcinomas and bronchioloalveolar carcinomas, and negative in atypical adenomatous hyperplasias. The higher frequency of expression in moderately/poorly differentiated adenocarcinomas suggests that insulin-like growth factor II mRNA binding protein 3 expression may be associated with an aggressive biological behavior.

Type I insulin-like growth factor receptor induces pulmonary tumorigenesis

Despite the type I insulin-like growth factor receptor (IGF-IR) being highly expressed in more than 80% of human lung tumors, a transgenic model of IGF-IR overexpression in the lung has not been created. We produced two novel transgenic mouse models in which IGF-IR is overexpressed in either lung type II alveolar cells (surfactant protein C [SPC]-IGFIR) or Clara cells (CCSP-IGFIR) in a doxycycline-inducible manner. Overexpression of IGF-IR in either cell type caused multifocal adenomatous alveolar hyperplasia with papillary and solid adenomas. These tumors expressed thyroid transcription factor 1 and Kruppel-like factor 5 in most tumor cells. Similar to our previous work with lung tumors that developed in the mouse mammary tumor virus-IGF-II transgenic mice, the lung tumors that develop in the SPC-IGFIR and CCSP-IGFIR transgenic mice expressed high levels of the cyclic adenosine monophosphate response element binding protein that was localized primarily to the nucleus. Although elevated IGF-IR expression can initiate lung tumor development, tumors can become independent of IGF-IR signaling as IGF-IR down-regulation in established tumors produced tumor regression in some, but not all, of the tumors. These findings implicate IGF-IR as an important initiator of lung tumorigenesis and suggest that the SPC-IGFIR and CCSP-IGFIR transgenic mice can be used to further our understanding of human lung cancer and the role IGF-IR plays in this disease.

IGF-II induces CREB phosphorylation and cell survival in human lung cancer cells

We have previously shown that lung tumors arising in MMTV-IGF-II transgenic mice displayed elevated levels of phosphorylated cAMP response element binding protein (CREB). To investigate the role that insulin-like growth factor II (IGF-II) and CREB play in human lung tumorigenesis, A549 and NCI-H358 cells were examined. In these cell lines, IGF-II administration enhances human tumor cell survival and CREB phosphorylation. Further, the effects of IGF-II on cell survival and CREB phosphorylation appeared to be mediated, at least in part, by activation of the Erk pathways, as inhibition of these signaling pathways reduced tumor cell survival and CREB phosphorylation. Specifically, Erk5 appeared as the predominant mediator of CREB phosporylation. To further verify the importance of CREB in human lung tumorigenesis, A549 and NCI-H358 cells were stably transfected with a vector containing a dominant negative CREB construct (KCREB). KCREB transfection significantly inhibited the soft agar growth of both human tumor cell lines. In contrast, overexpression of wild-type CREB in the normal human bronchial epithelial cell line, HBE135, enhanced soft agar growth. Therefore, our results indicate that CREB and its associated proteins play a significant role in lung adenocarcinoma and IGF-II induces CREB phosphorylation, at least in part, via the Erk5 signaling pathway.

Autocrine inhibition of chemotherapy response in human liver tumor cells by insulin-like growth factor-II

Insulin-like Growth Factor (IGF)-II is frequently overexpressed in experimental and human hepatocellular carcinomas (HCCs) and has been correlated with increased tumor growth. We have analyzed, whether IGF-II affects chemotherapy response and apoptosis in human liver tumor cells. Three liver tumor cell lines highly expressed IGF-II and supported their growth in an autocrine manner by secreting excessive amounts of IGF-II. Neutralization of IGF-II significantly increased response to the chemotherapeutic agents cisplatin and etoposide especially at lower, cytostatic doses. While blocking of IGF-II did not increase spontaneous cell death in exponentially growing cultures, increased cell death was found under conditions of confluent growth and chemotherapy. Thus in HCC cells, IGF-II is a relevant protumorigenic growth factor that significantly reduces susceptibility to apoptosis and chemotherapeutic treatment. Therefore interference with IGF-II activity may improve response of HCCs to otherwise inefficient chemotherapeutic agents.

Transgenic overexpression of IGF-II induces spontaneous lung tumors: a model for human lung adenocarcinoma

Elevated levels of insulin-like growth factor (IGF)-II are associated with a poor prognosis in human pulmonary adenocarcinoma; however, a causal role for IGF-II in pulmonary adenocarcinoma has not been demonstrated. Here, we show that transgenic overexpression of IGF-II in lung epithelium induces lung tumors in 69% of mice older than 18 months of age. These tumors displayed morphological characteristics of human pulmonary adenocarcinoma such as their epithelial origin, tubulo-acinar architecture and expression of TTF-1, SP-B and proSP-C. Examination of signaling molecules downstream of the IGF-IR showed the activation of either the Erk1/Erk2 or p38 MAPK pathways, but not both, within the lung tumors. Notably, all lung tumors contained high levels of phosphorylated CREB, suggesting that both the Erk1/Erk2 and p38 MAPK pathways converged on this transcription factor. Moreover, IGF-II induced proliferation and CREB phosphorylation in human lung cancer cell lines, suggesting that IGF-II and CREB also contribute to the growth of human lung tumors. Thus, IGF-II is an important genetic factor in the development of lung tumorigenesis, in which activation of CREB is a ubiquitous event. The MMTV-IGF-II transgenic mice provide a critical model for elucidating the role of IGF-II in this fatal human disease.

Prognostic factors in non-small cell lung cancer: a decade of progress

STUDY OBJECTIVES

To provide a systematic overview of the literature investigating patient and tumor factors that are predictive of survival for patients with non-small cell lung cancer (NSCLC), and to analyze patterns in the design of these studies in order to highlight problematic aspects of their design and to advocate for appropriate directions of future studies.

DESIGN

A systematic search of the MEDLINE database and a synthesis of the identified literature.

MEASUREMENTS AND RESULTS

The database search (January 1990 to July 2001) was carried out combining the MeSH terms prognosis and carcinoma, nonsmall cell lung. Eight hundred eighty-seven articles met the search criteria. These studies identified 169 prognostic factors relating either to the tumor or the host. One hundred seventy-six studies reported multivariate analyses. Concerning 153 studies reporting a multivariate analysis of prognostic factors in patients with early-stage NSCLC, the median number of patients enrolled per study was 120 (range, 31 to 1,281 patients). The median number of factors reported to be significant in univariate analyses was 4 (range, 2 to 14 factors). The median number of factors reported to be significant in multivariate analyses per study was 2 (range, 0 to 6 factors). The median number of studies examining each prognostic factor was 1 (range, 1 to 105 studies). Only 6% of studies addressed clinical outcomes other than patient survival.

CONCLUSIONS

While the breadth of prognostic factors studied in the literature is extensive, the scope of factors evaluated in individual studies is inappropriately narrow. Individual studies are typically statistically underpowered and are remarkably heterogeneous with regard to their conclusions. Larger studies with clinically relevant modeling are required to address the usefulness of newly available prognostic factors in defining the management of patients with NSCLC.

Association of preoperative plasma levels of insulin-like growth factor I and insulin-like growth factor binding proteins-2 and -3 with prostate cancer invasion, progression, and metastasis

PURPOSE

We tested the hypothesis that preoperative plasma levels of insulin-like growth factor (IGF) binding protein (BP)-2 or IGFBP-3 would predict cancer stage and prognosis in patients undergoing radical prostatectomy.

MATERIAL AND METHODS

Plasma levels of IGF-I, IGFBP-2, and IGFBP-3 were measured preoperatively in 120 consecutive patients who underwent radical prostatectomy for clinically localized disease, postoperatively in 51 of these patients, in 44 healthy men, in 19 patients with metastases to regional lymph nodes, and in 10 patients with bone metastases.

RESULTS

Plasma IGFBP-3 levels were lowest in patients with bone metastases (P < or = .043). IGFBP-2 levels were elevated in prostate cancer patients compared with healthy subjects (P < or = .006). However, within the group of prostatectomy patients, preoperative plasma IGFBP-2 levels were lower in patients with advanced disease (P < or = .033), were inversely correlated with prostatic tumor volume (P =.037), and declined after prostate removal (P =.044). Lower preoperative IGFBP-2 and IGFBP-3 levels and biopsy Gleason score were independent predictors of biochemical progression (P =.043, P =.040, and P =.020, respectively). In patients with disease progression, preoperative plasma IGFBP-3 levels were lower in those with aggressive than in those with nonaggressive failure (P =.042).

CONCLUSION

Elevation of plasma IGFBP-2 levels in prostate cancer patients apparently is due to increased release directly from the prostate. For patients with clinically localized prostate cancer, preoperative plasma IGFBP-2 levels are inversely associated with biologically aggressive disease and disease progression. Preoperative plasma IGFBP-3 levels were decreased in patients with prostate cancer metastases and were an independent predictor of biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.

Comparative immunohistochemical study of insulin-like growth factor II and insulin-like growth factor receptor type 1 in pediatric brain tumors

Insulin-like growth factor (IGF)-II is an important growth factor in development of the central nervous system. The purpose of this study was to evaluate expression of IGF-II and IGF receptor type 1 (IGFR1) in various pediatric brain tumors. Immunohistochemistry for IGF-II and IGFR1 was performed on 15 choroid plexus papillomas (CPPs) including 1 atypical CPP, 2 choroid plexus carcinomas (CPCs), 5 anaplastic ependymomas, 7 nonanaplastic ependymomas (simply referred to as "ependymoma"), 5 medulloblastomas, 1 cerebral neuroblastoma, and 1 atypical teratoid/rhabdoid tumor (ATRT) along with 10 non-neoplastic choroid plexus and 3 non-neoplastic ependymal linings. All non-neoplastic choroid plexus, CPPs, CPCs, anaplastic ependymomas, ATRT, 71% of ependymomas, and 67% of non-neoplastic ependymal linings showed cytoplasmic positivity for IGF-II, whereas all medulloblastomas and the cerebral neuroblastoma were negative for IGF-II. In addition to cytoplasmic positivity for IGFR1, membranous positivity was observed in 73% of CPPs, both CPCs, the ATRT, 22% of non-neoplastic choroid plexus, 80% of anaplastic ependymomas, and 29% of ependymomas, but not in any medulloblastoma, cerebral neuroblastoma, or non-neoplastic ependymal lining. IGF-II and IGFR1 may play roles in the pathogeneses of CPP, CPC, anaplastic ependymoma, ependymoma, and ATRT. Immunohistochemical testing for IGF-II and IGFR1 may be useful in differentiating ATRT, CPC, and anaplastic ependymoma from medulloblastoma and cerebral neuroblastoma.

Correlation of preoperative plasma IGF-I levels with pathologic parameters and progression in patients undergoing radical prostatectomy

OBJECTIVES

To test whether preoperative insulin-like growth factor (IGF)-I levels could predict pathologic stage and prognosis of prostate cancer in patients undergoing radical prostatectomy.

METHODS

The study group consisted of 120 consecutive patients who underwent radical prostatectomy for clinically localized prostate cancer. Preoperative plasma IGF-I levels were measured using the DSL-IGF-I Elisa assay. Surgically removed prostate specimens were analyzed pathologically, using a whole-mount step-section technique. Preoperative plasma IGF-I levels were compared with final pathologic parameters and with prostate-specific antigen (PSA) progression-free survival. Preoperative IGF-I levels in this cohort were also compared with IGF-I levels measured in 20 healthy men without any cancer and in 10 men with untreated, metastatic prostate cancer.

RESULTS

Plasma IGF-I levels predicted neither organ-confined disease (P = 0.5611) nor the risk of PSA progression (P = 0.8125) at a median follow-up of 48.6 months after prostatectomy. Furthermore, IGF-I levels did not correlate with preoperative PSA level (P = 0. 2811) or final Gleason score (P = 0.4906). IGF-I levels in radical prostatectomy patients were not significantly higher than those in healthy subjects or in patients with metastatic disease (mean 156.7 +/- 66 ng/mL, 148.6 +/- 49 ng/mL, and 148.6 +/- 93 ng/mL, respectively; P = 0.8442).

CONCLUSIONS

Circulating IGF-I levels may predict the future risk of developing prostate cancer, but our study found no association with other established markers of biologically aggressive disease or with disease progression in patients with clinically localized prostate cancer.