Prognostic role of insulin-like growth factor receptor-1 expression in small cell lung cancer

IGF1R and MAPK15 Emerge as Potential Targets of Pentabromobenzylisothioureas in Lung Neuroendocrine Neoplasms

Pentabromobenzylisothioureas are antitumor agents with diverse properties, including the inhibition of MAPK15, IGF1R and PKD1 kinases. Their dysregulation has been implicated in the pathogenesis of several cancers, including bronchopulmonary neuroendocrine neoplasms (BP-NEN). The present study assesses the antitumor potential of ZKKs, a series of pentabromobenzylisothioureas, on the growth of the lung carcinoid H727 cell line. It also evaluates the expression of MAPK15, IGF1R and PKD1 kinases in different BP-NENs. The viability of the H727 cell line was assessed by colorimetric MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) and its proliferation by BrdU (5-bromo-2′-deoxyuridine) assay. Tissue kinase expression was measured using TaqMan-based RT-PCR and immunohistochemistry. ZKKs (10⁻⁴ to 10⁻⁵ M) strongly inhibited H727 cell viability and proliferation and their antineoplastic effects correlated with their concentrations (p < 0.001). IGF1R and MAPK15 were expressed at high levels in all subtypes of BP-NENs. In addition, the SCLC (small cell lung carcinoma) patients demonstrated higher mRNA levels of IGF1R (p = 0.010) and MAPK15 (p = 0.040) than the other BP-NEN groups. BP-NENs were characterized by low PKD1 expression, and lung neuroendocrine cancers demonstrated lower PKD1 mRNA levels than carcinoids (p = 0.003). ZKKs may suppress BP-NEN growth by inhibiting protein kinase activity. Our results suggest also a possible link between high IGF1R and MAPK15 expression and the aggressive phenotype of BP-NEN tumors.

Prognostic value of IGF-1R in lung cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Insulin-like growth factor receptor 1 (IGF-1R) is a key player in a wide array of pathological processes, while the prognostic role of IGF-1R in lung cancer remains controversial.

METHODS

We conducted a meta-analysis to evaluate the prognostic value of IGF-1R in lung cancer. We searched for recent studies on the expression of IGF-1R and extracted prognostic lung cancer data from the articles.

RESULTS

Eventually, 22 studies with 3859 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to quantify the ability of IGF-1R to predict survival. The results indicated that IGF-1R positive expression was associated with an unfavorable disease-free survival (DFS) in non-small cell lung cancer (NSCLC) patients on univariate analysis (HR = 1.24, 95% CI: 1.00-1.55, P = .054) and multivariate analysis (HR = 1.49, 95% CI: 1.01-2.21, P = .045), but there was no significant difference in the relationship between IGF-1R positive expression and overall survival (OS) on univariate analysis (HR = 1.04, 95% CI: 0.86-1.25, P = .712) and multivariate analysis (HR = 0.89, 95% CI: 0.57-1.39, P = .602). IGF-1R mRNA expression related to OS was obtained in 2 studies, with the pooled HR being 1.663 (95% CI: 1.071-2.583, P = .024). For IGF-1R expression and small cell lung cancer (SCLC), the conclusion was not statistically significant, with the pooled HR being 1.22 (95% CI: 0.66-2.27, P = .524).

CONCLUSIONS

Our results indicate that high expression of IGF-1R predicts poor DFS in NSCLC, yet it does not predict poor OS in NSCLC and SCLC. IGF-1R may be a useful predictor of outcomes in patients with NSCLC.

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.

Increased insulin-like growth factor 1 receptor (IGF1R) expression in small cell lung cancer and the effect of inhibition of IGF1R expression by RNAi on growth of human small cell lung cancer NCI-H446 cell

Insulin-like growth factor 1 receptor (IGF1R) is a tyrosine kinase receptor implicated in tumourigenesis that may be an attractive target for anti-cancer treatment. In this study, the expression and clinical significance of IGF1R were investigated in serum and lung cancer tissues from small cell lung cancinoma (SCLC). We also compared the effect of IGF1R up-regulation and IGF1R inhibition on viability and apoptosis of NCI-H446 cells. We found the concentration of IGF1R in blood serum was significantly increased and positive IGF1R protein in cancer tissue was more prevalent in SCLC. A statistically significant correlation among IGF1R-positve tumors, lymph node metastasis and local invasion was discussed. Furthermore, IGF1R overexpression lead to an increase of cell survival and suppressed cell apoptosis, IGF1R silencing mediated by RNAi abrogate this response of NCI-H446 cells. Our results further demonstrated that the effects of these treatments may be assigned to the effective inhibition of lung cancer cells from Akt/P27(Kip1) pathway in IGF-1R signaling. These features may have important implications for future anti-IGF1R therapeutic approaches.

Expression pattern and prognostic significance of IGFBP isoforms in anaplastic astrocytoma

The role of insulin-like growth factors and their regulatory proteins (IGFBP isoforms) in gliomas, particularly glioblastoma, has been a subject of active research in recent years. There is paucity of literature on their expression and impact on clinical outcome in anaplastic astrocytomas. To evaluate the expression patterns of IGFBP isoforms in anaplastic astrocytoma and correlate with clinical outcome, a retrospective study of 53 adult patients operated for supratentorial lobar anaplastic astrocytoma was performed. The protein expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7), was studied by immunohistochemistry on all samples. The patients were followed up and outcome was documented. The median age at presentation in the present study was 35 years. The pattern of staining was intra cytoplasmic, homogenous and diffuse for IGFBP-2, -3 and -5 and granular for IGFBP-7. IGFBP-2 expression was significantly low in anaplastic astrocytoma as compared to other isoforms (P < 0.001). IGFBP-3 expression was higher than the other isoforms. However, its' expression correlated with favorable overall survival and demonstrated a trend towards significance on univariate analysis. The present study is the first of its kind to describe comprehensively the pattern of expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7) in anaplastic astrocytomas. IGFBP-2 and IGFBP-3 expression patterns and correlation to prognosis were distinct in anaplastic astrocytoma patients, contradictory to what has been reported in glioblastoma, thus giving further evidence that anaplastic astrocytomas are molecularly distinct from glioblastoma.

Clinical significance of IGF1R expression in non-small-cell lung cancer

BACKGROUND

The purpose of the current study was to clarify the clinical role of insulin-like growth factor receptor-1 (IGF1R) in NSCLC.

PATIENTS AND METHODS

Tumor specimens were collected from 285 patients who underwent complete resection for adenocarcinoma (AD, n = 182), squamous cell carcinoma (SCC, n = 77), and other histologic types of cancer (n = 26) of the lung. The expression of IGF1R and Ki-67 was evaluated by immunohistochemical (IHC) analysis.

RESULTS

Positive expression of IGF1R was detected in 87 (30.5%) of 285 cases, of which 43 (23.6%) of 182 cases were AD, 36 (46.8%) of 77 cases were SCC, and 8 (30.8%) of 26 cases were other histologic types (SCC vs. AD, p < .001; SCC vs. non-SCC, p < .001). Positive IGF1R expression was also identified in 20 (44.4%) and 67 (27.9%) of the patients with and without recurrence, respectively (p = .027). Multivariate logistic regression models indicated that positive staining for IGF1R expression was an independent factor in AD associated with tumor recurrence (p = .040) but not in NSCLC, SCC, and other types of cancer. A positive IGF1R expression tended to demonstrate a poor disease-free survival (DFS) in NSCLC according to the Kaplan-Meier DFS curves (p = .053). The tumors showing a positive expression of IGF1R were observed more frequently in tumors with a positive expression of Ki-67 than in the tumors with a negative expression of Ki-67 (p = .010).

CONCLUSION

IGF1R expression was associated with reduced DFS correlating with postoperative recurrence. In addition, a significant relationship was also observed between IGF1R and Ki-67 expression in NSCLC. However, in subgroup analysis, a significant correlation was not observed. IGF1R expression predicts postoperative recurrence in patients with AD, but not in those with non-AD of NSCLC.

Molecular pathways of lymphangiogenesis and lymph node metastasis in head and neck cancer

Metastasis to regional lymph nodes constitutes the main route toward progression and dissemination of head and neck carcinoma; at the same time it is the most significant adverse prognostic indicator for this disease. In recent years, significant focus has been given on the molecular mechanisms behind lymph node metastasis of head and neck cancer. The aim of this study is to assess the role of growth factor expression and function in association with lymph node metastasis and overall prognosis of head and neck cancer. Current literature, searching for experimental data regarding the molecular pathways of lymph node dissemination of head and neck cancer, is reviewed giving special emphasis on the expression and prognostic significance of specific growth factors. Members of the vascular endothelial growth factor (VEGF), mostly VEGF-C and VEGF-D, with their action through the receptors VEGFR-3 and VEGFR-2, constitute the most extensively studied growth factors associated with lymphangiogenesis so far. High expression of these as well as other molecules, including angiopoietins, insulin-like growth factor, and fibroblast growth factor, has been associated with lymph node metastasis and poor prognosis in head and neck squamous cell carcinoma. Numerous growth factors seem to play an important role regarding the lymph node metastatic potential of head and neck cancer. Further research is necessary in order to further clarify the molecular pathways and introduce novel therapeutic options.

Prognostic impact of insulin receptor expression on survival of patients with nonsmall cell lung cancer

BACKGROUND

The purpose of this study was to characterize insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF-1R) expression in patients with nonsmall cell lung cancer (NSCLC).

METHODS

A total of 459 patients who underwent curative resection of NSCLC were studied (median follow-up duration, 4.01 years). Expression of the IR and IGF-1R protein in tumor specimens was assessed immunohistochemically using tissue microarrays.

RESULTS

The cytoplasmic IR score was higher in patients with adenocarcinoma (ADC) than in those with squamous cell carcinoma (SCC), whereas cytoplasmic IGF-1R score was higher in patients with SCC than those with ADC. Neither IR nor IGF-1R expression was associated with sex, smoking history, or clinical stage. Patients with positive IR or IGF-1R expression levels had poor recurrence-free (RFS) (3.8 vs 3.3 years; 3.8 vs 2.0 years, respectively), but similar overall survival (OS). Patients with high expression levels of IR and IGF-1R had shorter RFS and OS compared with those with low levels of IR and/or IGF-1R expression. Finally, a multivariate analysis revealed the impact of IR, but not of IGF-1R, as an independent predictive marker of NSCLC survival: hazard ratio (HR) for OS, 1.005 (95% confidence interval [CI], 1.001-1.010], HR for RFS, 1.005 (95% CI, 1.001-1.009), when IR score was tested as a continuous variable.

CONCLUSIONS

Overexpression of IR predicts a poor survival among patients with NSCLC, especially those with SCC. These results might serve as future guidance to the clinical trials involving IR or IGR-1R targeting agents.

Insulin-like growth factor receptor-1 expression predicts postoperative recurrence in adenocarcinoma of the lung

Not all patients with lung cancer require postoperative adjuvant chemotherapy after a complete resection. However, no useful markers exist for either selecting appropriate candidates or for predicting clinical recurrence. The purpose of the present study was to clarify the clinical role of insulin-like growth factor receptor-1 (IGFR1) in lung adenocarcinoma. Tumor specimens were collected from 182 patients who underwent a complete resection for adenocarcinoma of the lung. The expression of IGFR1 was evaluated by immunohistochemistry. The genetic status of the epidermal growth factor receptor (EGFR) and K-ras genes was also investigated by PCR-based analyses. Immunohistochemistry and real-time PCR assays were used to evaluate the MET gene association with tyrosine phosphorylation and hepatocyte growth factor (HGF) status, and amplification, respectively. Positive expression of IGFR1 was detected in 43 (23.6%) of the 182 cases. A positive IGFR1 expression was also identified in 12 (42.9%) and 31 (20.1%) of the patients with and without recurrence, respectively (p=0.009). Logistic regression models indicated that positive staining for IGFR1 expression was an independent factor associated with tumor recurrence. IGFR1 expression was associated with a poorer disease-free survival (DFS). Multivariate analysis demonstrated positive IGFR1 expression to be independently associated with an increased risk for poor DFS. The tumors appearing positive for IGFR1 were more frequent among those with K-ras mutations when compared with the wild-type group. IGFR1 expression was associated with reduced DFS correlating with postoperative recurrence. Therefore, the expression status of IGFR1 can be a candidate surrogate marker to select patients who may benefit from adjuvant chemotherapy.

Increased insulin-like growth factor 1 receptor protein expression and gene copy number in small cell lung cancer

PURPOSE

Identification of new therapies in small cell lung cancer (SCLC) is urgently needed. Insulin-like growth factor 1 receptor (IGF1R) is a tyrosine kinase receptor implicated in the pathogenesis of several malignancies and is potentially an attractive target for anticancer treatment. Knowledge about IGF1R protein expression, gene copy number, and the prognostic relevance of these features in SCLC is limited.

METHODS

We analyzed IGF1R protein expression and gene copy number in primary tumors from 90 patients with SCLC (67 men and 23 women) who underwent pulmonary resection. IGF1R expression assessed by immunohistochemistry with H scores from 0 to 400 was evaluable in 84 patients and IGF1R gene copy number assessed by silver in situ hybridization technique in 81 patients.

RESULTS

Median H score for IGF1R protein expression was 88 (range, 0-400), and the proportion of positive immunostaining using cutoff H score of 10 was 74%. Increased IGF1R gene copy number (an average of four or more copies per cell) was found in 15 cases (18.5%), five of whom (6.2%) showed gene amplification. There was a significant correlation between protein expression and gene copy number (r = 0.49, p < 0.005). IGF1R expression and gene copy number did not associate with clinicopathological factors such as patient age, tumor size, lymph node involvement, stage, and survival.

CONCLUSIONS

SCLC is characterized by frequent high-IGF1R protein expression, increased gene copy number, and occasional occurrence of true gene amplification. These features may have important implications for future anti-IGF1R therapeutic approaches.