High Coexpression of Both EGFR and IGF1R Correlates With Poor Patient Prognosis in Resected Non–Small-Cell Lung Cancer

Establishing a new human lung squamous cell carcinoma cell line, OMUL-1, expressing insulin-like growth factor 1 receptor and programmed cell death ligand 1

THE MAIN PROBLEM

Squamous cell carcinoma is the second most prevalent type of non-small cell lung cancer. Analyzing the molecular mechanisms underlying lung carcinoma requires useful tools, such as squamous lung cancer cell lines.

METHODS

A novel new lung squamous cell carcinoma cell line, OMUL-1, was developed from the primary lung cancer of a 74-year-old man. We assessed the characteristics and behavior of OMUL-1 cells were examined, including their growth kinetics, tumorigenicity in mice, histological properties, gene expression profiles using reverse transcription polymerase chain reaction (RT-PCR), and RNA sequencing and invasion assays.

RESULTS

OMUL-1-an adherent cell line-resulted in 100% tumor formation when subcutaneously injected into mice. Histological analysis of the subcutaneous tumor using hematoxylin and eosin staining revealed squamous cell carcinoma with characteristics similar to those of the primary tumor (p40 and p63 were positive, and TTF-1 was negative). An invasion assay demonstrated that OMUL-1 had a lower invasion ability compared to that of other developed cell lines. RT-PCR analysis and RNA sequencing indicated that OMUL-1 cells expressed FGFR1, FGFR2, FGFR3, FGFR4, EGFR, HER2, ErbB3, ErbB4, VEGFR3, IGF1R, c-MET, PDGFRa, and PDGFRb. Additionally, picropodophyllin (an IGF1R inhibitor) significantly inhibited the growth of OMUL-1 cells. Immunohistochemistry revealed that IGF1R and PD-L1 were expressed in both the primary and subcutaneous tumors.

CONCLUSIONS

We developed a novel new squamous cell lung carcinoma cell line, OMUL-1, that expresses IGF1R and PD-L1.

Insulin-like growth factor 1 receptor expression correlates with programmed death ligand 1 expression and poor survival in non-small cell lung cancer

The insulin-like growth factor 1 receptor (IGF1R) has been associated with growth and metastasis in various cancers. However, its role in postoperative recurrence and prognosis in lung cancer lacks clear consensus. Therefore, this study aimed to investigate the potential relationship between IGF1R and postoperative recurrence as well as long-term survival in a large cohort. Additionally, we assessed the relationship between IGF1R and programmed death ligand 1 (PD-L1) expression. Our study encompassed 782 patients with non-small cell lung cancer (NSCLC). Immunostaining of surgical specimens was performed to evaluate IGF1R and PD-L1 expression. Among the patients, 279 (35.8%) showed positive IGF1R expression, with significantly worse relapse-free survival (RFS) and overall survival (OS). Notably, no significant differences in RFS and OS were observed between IGF1R-positive and -negative groups in stages 2 and 3. However, in the early stages (0-1), the positive group displayed significantly worse RFS and OS. In addition, PD-L1 expression was detected in 100 (12.8%) patients, with a significant predominance in the IGF1R-positive. IGF1R may serve as a prognostic indicator and a guide for perioperative treatment strategies in early-stage lung cancer. In conclusion, our findings underscore an association between IGF1R expression and poor survival and PD-L1 expression in NSCLC.

Insulin resistance in NSCLC: unraveling the link between development, diagnosis, and treatment

Lung cancer is responsible for the highest number of cancer-related deaths, with non-small cell lung cancer (NSCLC) being the most prevalent subtype. A critical aspect of managing lung cancer is reducing morbidity and mortality rates among NSCLC patients. Identifying high-risk factors for lung cancer and facilitating early diagnosis are invaluable in achieving this objective. Recent research has highlighted the association between insulin resistance and the development of NSCLC, further emphasizing its significance in the context of lung cancer. It has been discovered that improving insulin resistance can potentially inhibit the progression of lung cancer. Consequently, this paper aims to delve into the occurrence of insulin resistance, the mechanisms underlying its involvement in lung cancer development, as well as its potential value in predicting, assessing, and treating lung cancer.

Mechanism and recent updates on insulin-related disorders

Insulin, a small protein with 51 amino acids synthesized by pancreatic β-cells, is crucial to sustain glucose homeostasis at biochemical and molecular levels. Numerous metabolic dysfunctions are related to insulin-mediated altered glucose homeostasis. One of the significant pathophysiological conditions linked to the insulin associated disorder is diabetes mellitus (DM) (type 1, type 2, and gestational). Insulin resistance (IR) is one of the major underlying causes of metabolic disorders despite its association with several physiological conditions. Metabolic syndrome (MS) is another pathophysiological condition that is associated with IR, hypertension, and obesity. Further, several other pathophysiological disorders/diseases are associated with the insulin malfunctioning, which include polycystic ovary syndrome, neuronal disorders, and cancer. Insulinomas are an uncommon type of pancreatic β-cell-derived neuroendocrine tumor that makes up 2% of all pancreatic neoplasms. Literature revealed that different biochemical events, molecular signaling pathways, microRNAs, and microbiota act as connecting links between insulin disorder and associated pathophysiology such as DM, insuloma, neurological disorder, MS, and cancer. In this review, we focus on the insulin-related disorders and the underlying mechanisms associated with the pathophysiology.

Identification of EGFR-Related LINC00460/mir-338-3p/MCM4 Regulatory Axis as Diagnostic and Prognostic Biomarker of Lung Adenocarcinoma Based on Comprehensive Bioinformatics Analysis and Experimental Validation

Background: Lung adenocarcinoma (LUAD) is one of the most aggressive and lethal tumor types and requires effective diagnostic and therapeutic targets. Though the epidermal growth factor receptor (EGFR) is an important target for LUAD therapy, acquired resistance is still inevitable. In recent years, the regulation of the EGFR by competing endogenous RNAs (ceRNAs) has been extensively studied and significant progress has been made. Therefore, we aim to find new targets for the diagnosis and treatment of LUAD by analyzing the EGFR-related ceRNA network in LUAD and expect to address the problem of EGFR resistance. Methods: We identified differentially expressed lncRNAs, miRNAs and mRNAs closely associated with the EGFR by analyzing transcriptome data from LUAD samples. Comprehensive bioinformatics analysis strongly suggests that the LINC00460-mir-338-3p-MCM4 ceRNA network plays an important role in the diagnosis and prognosis of LUAD. The effects of different patterns of the LINC00460/MCM4 axis on the overall survival of patients with LUAD were analyzed by a polygene regulation model. We also verified the expression of these genes in LUAD cell lines and tumor tissues by RT-PCR and immunohistochemistry. The functional enrichment analysis and targeted drug prediction of the MCM4 gene were performed. Results: Survival analysis indicated that high expressions of LINC00460 and MCM4 predict a shorter survival period for patients. Univariate and multivariate regression analyses demonstrated that higher expressions of LINC00460 and MCM4 were significantly associated with tumor size, lymph node metastasis, distant metastasis and TNM stage. A multi-gene regulation model analysis revealed that the LINC00460 (downregulation)-mir-338-3p (upregulation)-MCM4 (downregulation) pattern significantly improved the overall survival of LUAD patients (p = 0.0093). RT-PCR and immunohistochemical experiments confirmed our analytical results. In addition, the functional enrichment analysis indicated that MCM4-related genes were mainly enriched in the cell cycle and cell division. A functional association network analysis showed that MCM4 was closely related to the EGFR. Finally, the possible targeted drugs of MCM4 were queried through the drug database platform, hoping to solve its drug resistance problem by targeting EGFR-related genes. Conclusions: In summary, the LINC00460/MCM4 axis can be used as a potential new perspective for targeting EGFR genes in precision medicine and is expected to serve as a diagnostic, prognostic and drug target for LUAD.

Different roles of the insulin-like growth factor (IGF) axis in non-small cell lung cancer

Abstract:

Non-small cell lung cancer (NSCLC) remains one of the deadliest malignant diseases, with high incidence and mortality worldwide. The insulin-like growth factor (IGF) axis, consisting of IGF-1, IGF-2, related receptors (IGF-1R, -2R), and high-affinity binding proteins (IGFBP 1–6), is associated with promoting fetal development, tissue growth, and metabolism. Emerging studies have also identified the role of the IGF axis in NSCLC, including cancer growth, invasion, and metastasis. Upregulation of IGE-1 and IGF-2, overexpression of IGF-1R, and dysregulation of downstream signaling molecules involved in the PI-3K/Akt and MAPK pathways jointly increase the risk of cancer growth and migration in NSCLC. At the genetic level, some noncoding RNAs could influence the proliferation and differentiation of tumor cells through the IGF signaling pathway. The resistance to some promising drugs might be partially attributed to the IGF axis. Therapeutic strategies targeting the IGF axis have been evaluated, and some have shown promising efficacy. In this review, we summarize the biological roles of the IGF axis in NSCLC, including the expression and prognostic significance of the related components, noncoding RNA regulation, involvement in drug resistance, and therapeutic application. This review offers comprehensive understanding of NSCLC and provides insightful ideas for future research.

Targeted Therapies in Lung Cancers: Current Landscape and Future Prospects

BACKGROUND

Lung cancer is the most common and malignant cancer worldwide. Targeted therapies have emerged as a promising treatment strategy for lung cancers.

OBJECTIVE

The objective of this study is to evaluate the current landscape of targets and finding promising targets for future new drug discovery for lung cancers by identifying the science-technology-clinical development pattern and mapping the interaction network of targets.

METHODS

Targets for cancers were classified into 3 groups based on a paper published in Nature. We search for scientific literature, patent documents and clinical trials of targets in Group 1 and Group 2 for lung cancers. Then, a target-target interaction network of Group 1 was constructed, and the science-technology-clinical(S-T-C) development patterns of targets in Group 1 were identified. Finally, based on the cluster distribution and the development pattern of targets in Group 1, interactions between the targets were employed to predict potential targets in Group 2 on drug development.

RESULTS

The target-target interaction(TTI)network of group 1 resulted in 3 clusters with different developmental stages. The potential targets in Group 2 are divided into 3 ranks. Level-1 is the first priority and level-3 is the last. Level-1 includes 16 targets, such as STAT3, CRKL, and PTPN11, that are mostly involved in signaling transduction pathways. Level-2 and level-3 contain 8 and 6 targets related to various biological functions.

CONCLUSION

This study will provide references for drug development in lung cancers, emphasizing that priorities should be given to targets in Level-1, whose mechanisms are worth further exploration.

Notch Transduction in Non-Small Cell Lung Cancer

The evolutionarily-conserved Notch signaling pathway plays critical roles in cell communication, function and homeostasis equilibrium. The pathway serves as a cell-to-cell juxtaposed molecular transducer and is crucial in a number of cell processes including cell fate specification, asymmetric cell division and lateral inhibition. Notch also plays critical roles in organismal development, homeostasis, and regeneration, including somitogenesis, left-right asymmetry, neurogenesis, tissue repair, self-renewal and stemness, and its dysregulation has causative roles in a number of congenital and acquired pathologies, including cancer. In the lung, Notch activity is necessary for cell fate specification and expansion, and its aberrant activity is markedly linked to various defects in club cell formation, alveologenesis, and non-small cell lung cancer (NSCLC) development. In this review, we focus on the role this intercellular signaling device plays during lung development and on its functional relevance in proximo-distal cell fate specification, branching morphogenesis, and alveolar cell determination and maturation, then revise its involvement in NSCLC formation, progression and treatment refractoriness, particularly in the context of various mutational statuses associated with NSCLC, and, lastly, conclude by providing a succinct outlook of the therapeutic perspectives of Notch targeting in NSCLC therapy, including an overview on prospective synthetic lethality approaches.

Bioinformatics Analysis of Microarray Datasets to Identify Prognostic Factors in Lung Adenocarcinoma

Most patients with lung adenocarcinoma (LUAD) present high recurrence rate and poor prognosis after therapy. Therefore, the purpose of this study was to identify prognostic factors involved in LUAD. Five microarray datasets (including GSE75037, GSE63459, GSE43458, GSE32863, and GSE10072) were downloaded. After data preprocessing and quality control, meta-analysis was performed to screen differentially expressed genes (DEGs) using the MetaDE.ES method in MetaDE package. Subsequently, network construction and module identification were conducted by the Weighted Gene Co-expression Network Analysis method. Moreover, survival-associated genes were identified using the univariate and multivariate Cox regression method in survival package. The risk score model was constructed by prognosis associated genes, followed by the Kaplan-Meier survival analysis. Oncomine expressions analysis of several prognosis associated genes was conducted. The expression levels of key genes were detected using quantitative real-time PCR experiments. A total of 1434 DEGs between LUAD and normal samples were identified. Nine disease-associated modules were identified, in which M8 module was most correlated with LAUD phenotype. A total of 89 indicators (including T stage, M stage, and ADIPOR2) were significantly associated with LAUD prognosis, while only T stage and 9 DEGs (e.g., ARHGEF3, GTSE1, RBM15 and CD52) were retained as the potential prognostic factors following multivariate COX regression analysis. The upregulated adiponectin receptor 2 (ADIPOR2), rho guanine nucleotide exchange factor 3 (ARHGEF3), and CD52 molecule (CD52), and downregulated GTSE1 were validated in LAUD samples of Oncomine database. Importantly, ADIPOR2 and ARHGEF3 were confirmed to be down-regulated in LUAD tissues. ADIPOR2, ARHGEF3, G2 and S-phase expressed 1 (GTSE1) and CD52 might be promising prognostic factors in LUAD.

Combination therapy of gefitinib and miR-30a-5p may overcome acquired drug resistance through regulating the PI3K/AKT pathway in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) patients with an epidermal growth factor receptor (EGFR) mutation often initially respond to EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment but may acquire drug resistance due to multiple factors. MicroRNAs are a class of small noncoding and endogenous RNA molecules that may play a role in overcoming the resistance.

MATERIALS AND METHODS

In this study, we explored and validated, through in vitro experiments and in vivo models, the ability of a combination treatment of EGFR-TKI, namely gefitinib, and a microRNA mimic, miR-30a-5p, to overcome drug resistance through regulation of the insulin-like growth factor receptor-1 (IGF1R) and hepatocyte growth factor receptor signaling pathways, which all converge on phosphatidylinositol 3 kinase (PI3K), in NSCLC. First, we examined the hypothesized mechanisms of drug resistance in H1650, H1650-acquired gefitinib-resistance (H1650GR), H1975, and H460 cell lines. Next, we investigated a potential combination treatment approach to overcome acquired drug resistance in the H1650GR cell line and an H1650GR cell implanted mouse model.

RESULTS

Dual inhibitors of EGFR and IGF1R significantly lowered the expression levels of phosphorylated protein kinase B (p-AKT) and phosphorylated mitogen-activated protein kinase (p-ERK) compared with the control group in all cell lines. With the ability to repress PI3K expression, miR-30a-5p mimics induced cell apoptosis, and inhibited cell invasion and migration in the treated H1650GR cell line.

CONCLUSION

Gefitinib, combined with miR-30a-5p mimics, effectively suppressed the growth of H1650GR-induced tumor in xenografts. Hence, a combination therapy of gefitinib and miR-30a-5p may play a critical role in overcoming acquired resistance to EGFR-TKIs. The reviews of this paper are available via the supplemental material section.

Insulin Receptor Substrate-1 (IRS-1) and IRS-2 expression levels are associated with prognosis in non-small cell lung cancer (NSCLC)

The insulin-like growth factor-1 (IGF-1) signaling pathway has been implicated in non-small cell lung cancer (NSCLC) outcomes and resistance to targeted therapies. However, little is known regarding the molecular mechanisms by which this pathway contributes to the biology of NSCLC. The insulin receptor substrate (IRS) proteins are cytoplasmic adaptor proteins that signal downstream of the IGF-1R and determine the functional outcomes of this signaling pathway. In this study, we assessed the expression patterns of IRS-1 and IRS-2 in NSCLC to identify associations between IRS-1 and IRS-2 expression levels and survival outcomes in the two major histological subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC). High IRS-2 expression was significantly associated with decreased overall survival in adenocarcinoma (ADC) patients, whereas low IRS-1 cytoplasmic expression showed a trend toward association with decreased overall survival in squamous cell carcinoma (SCC) patients. Tumors with low IRS-1 and high IRS-2 expression were found to be associated with poor outcomes in ADC and SCC, indicating a potential role for IRS-2 in the aggressive behavior of NSCLC. Our results suggest distinct contributions of IRS-1 and IRS-2 to the biology of ADC and SCC that impact disease progression.

MicroRNA-877 inhibits cell proliferation and invasion in non-small cell lung cancer by directly targeting IGF-1R

MicroRNAs (miRNAs/miRs) are frequently differentially expressed in non-small cell lung cancer (NSCLC), and differential miRNAs expression may be closely associated with NSCLC genesis and development. Therefore, an in-depth investigation of the cancer-associated miRNAs that are crucial for NSCLC pathogenesis may provide effective therapeutic targets for patients with this aggressive malignant tumor type. The expression levels and roles of miR-877 have been well studied in hepatocellular carcinoma and renal cell carcinoma. However, the expression pattern and functions of miR-877 in NSCLC as well as associated underlying mechanisms, to the best of our knowledge, have not yet been investigated. The present study revealed that miR-877 expression was downregulated in NSCLC tissues and cell lines. Low miR-877 expression was significantly associated with TNM stage and distant metastasis in patients with NSCLC. Functional experiments demonstrated that recovery of miR-877 expression restricted the proliferation and invasion of NSCLC cells. In addition, bioinformatics analysis predicted insulin-like growth factor 1 receptor (IGF-1R) as a potential target of miR-877. Luciferase reporter assays, reverse transcription-quantitative PCR and western blot analysis further validated that IGF-1R was a direct target of miR-877 in NSCLC. Furthermore, IGF-1R expression was markedly upregulated in NSCLC tissues, and exhibited an inverse correlation with miR-877 expression. Additionally, IGF-1R overexpression reversed the inhibitory effects in NSCLC cells caused by miR-877 upregulation. These findings demonstrated that miR-877 attenuated NSCLC cell proliferation and invasion, at least partly, by downregulating IGF-1R expression, thereby providing an new candidate biomarker for the diagnosis and therapy of patients with NSCLC.

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.

Bladder cancer cells interact with vascular endothelial cells triggering EGFR signals to promote tumor progression

Although important progress has been made in elucidating the role of the tumor microenvironment in the development of bladder cancer, little is currently known regarding the interactions with vascular endothelial cells (ECs) that promote cancer progression. In the present study, it is reported that epidermal growth factor receptor ligands induced by the upregulation of vascular endothelial growth factor (VEGF)-A and VEGF-C via the VEGF receptor (R)2/nuclear factor-κB signaling pathway in ECs, may trigger EGFR signaling in bladder cancer cells and promote bladder cancer progression. Furthermore, the interaction between bladder cancer cells and ECs enhanced EC recruitment though the CXCL1/CXCL5/CXCL8-CXCR2 pathway. Western blotting was used to evaluate the presence of VEGFR, EGFR and nuclear factor-κB, and reverse transcription-quantitative polymerase chain reaction was used to evaluate the expression of VEGFR ligands and EGFR ligands. The present results indicate the mechanism by which the indirect interplay between bladder cancer cells and vascular ECs promotes cancer progression, through the VEGFR2 signaling pathway in vascular ECs and through the EGFR signaling pathway in bladder cancer cells.

Development of treatment options for Chinese patients with advanced squamous cell lung cancer: focus on afatinib

Lung cancer is the leading cause of cancer death in China, and approximately one third of these cancers are squamous cell carcinoma (SqCC) of the lung. Ethnic diversity and country-specific environmental factors can account for interindividual variations in response to and tolerability of anticancer therapies. Although several targeted therapies have recently been approved for patients with relapsed/refractory SqCC of the lung, only afatinib, an irreversible ErbB family blocker, has data of Chinese patients. In the Phase III LUX-Lung 8 trial, afatinib demonstrated a significant clinical benefit vs the reversible first-generation EGFR tyrosine kinase inhibitor erlotinib in both the overall population and the Chinese subset, with a manageable safety profile. Emerging biomarker data from LUX-Lung 8 suggest that patients with ErbB mutations, especially ErbB2, and those classified as “good” in the VeriStrat^® proteomic test, may benefit from afatinib treatment in particular, regardless of ethnicity, and may get a long-term response. In conclusion, afatinib is a valid second-line option for Chinese patients with SqCC of the lung, and specific biomarkers may help guide in treatment decision-making. Ongoing studies will provide further guidance on afatinib’s place in the treatment algorithm, alongside the other novel targeted therapies.

Inhibition of COX-2 and EGFR by Melafolone Improves Anti-PD-1 Therapy through Vascular Normalization and PD-L1 Downregulation in Lung Cancer

Checkpoint blockade therapy has been proven efficacious in lung cancer patients. However, primary/acquired resistance hampers its efficacy. Therefore, there is an urgent need to develop novel strategies to improve checkpoint blockade therapy. Here we tested whether dual inhibition of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) by flavonoid melafolone improves program death 1 (PD-1) checkpoint blockade therapy through normalizing tumor vasculature and PD-1 ligand (PD-L1) downregulation. Virtual screening assay, cellular thermal shift assay, and enzyme inhibition assay identified melafolone as a potential inhibitor of COX-2 and EGFR. In Lewis lung carcinoma (LLC) and CMT167 models, dual inhibition of COX-2 and EGFR by melafolone promoted survival, tumor growth inhibition, and vascular normalization, and ameliorated CD8⁺ T-cell suppression, accompanied by the downregulation of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and PD-L1 in the tumor cells. Mechanistically, dual inhibition of COX-2 and EGFR in lung cancer cells by melafolone increased the migration of pericyte, decreased the proliferation and migration of endothelial cells, and enhanced the proliferation and effector function of CD8⁺ T cells through VEGF, TGF-β, or PD-L1 downregulation and PI3K/AKT inactivation. Notably, melafolone improved PD-1 immunotherapy against LLC and CMT167 tumors. Together, dual inhibition of COX-2 and EGFR by melafolone improves checkpoint blockade therapy through vascular normalization and PD-L1 downregulation and, by affecting vessels and immune cells, may be a promising combination strategy for the treatment of human lung cancer.

Clinical features of squamous cell lung cancer with anaplastic lymphoma kinase (ALK)-rearrangement: a retrospective analysis and review

Anti-anaplastic lymphoma kinase (ALK)-targeted therapy dramatically improves therapeutic responses in patients with ALK-rearranged lung adenocarcinoma (Ad-LC). A few cases of squamous cell lung carcinoma (Sq-LC) with ALK rearrangement have been reported; however, the clinicopathological features and clinical outcomes following treatment with ALK inhibitors are unknown. We addressed this in the present study by retrospectively comparing the clinical characteristics of five patients with ALK-rearranged Sq-LC with those of patients with ALK-rearranged Ad-LC and by evaluating representative cases of ALK inhibitor responders and non-responders. The prevalence of ALK rearrangement in Sq-LCs was 1.36%. Progression-free survival (PFS) after initial treatment with crizotinib was significantly shorter in Sq-LC than in Ad-LC with ALK rearrangement (p = 0.033). Two ALK rearrangements assayed by fluorescence in situ hybridization (FISH)-positive/immunohistochemistry-negative cases did not respond to crizotinb, and PFS decreased following alectinib treatment of ALK-rearranged Sq-LC (p = 0.045). A rebiopsy revealed that responders to ceritinib harbored the L1196M mutation, which causes resistance to other ALK inhibitors. However, non-responders were resistant to all ALK inhibitors, despite the presence of ALK rearrangement in FISH-positive circulating tumor cells and circulating free DNA and absence of the ALK inhibitor resistance mutation. These results indicate that ALK inhibitors remain a reasonable therapeutic option for ALK-rearranged Sq-LC patients who have worse outcomes than ALK-rearranged Ad-LC patients and that resistance mechanisms are heterogeneous. Additionally, oncologists should be aware of the possibility of ALK-rearranged Sq-LC based on clinicopathological features, and plan second-line therapeutic strategies based on rebiopsy results in order to improve patient outcome.

Clinical efficacy and safety of afatinib in the treatment of non-small-cell lung cancer in Chinese patients

Compared with various malignant tumors, lung cancer has high incidence and the highest mortality worldwide. Non-small-cell lung cancer (NSCLC), the most common kind of lung cancer, is still a great threat to the world, including China. Surgery, platinum-based chemotherapy, and radiotherapy are still the primary treatments for NSCLC patients in the clinic, whereas immunotherapy and targeted therapy are gradually playing more important roles. A next-generation tyrosine kinase inhibitor (TKI), afatinib, was developed as a targeted reagent for epidermal growth factor receptor (EGFR). This targeted drug was effective in a series of trials. The US Food and Drug Administration then approved afatinib as a new first-line treatment for EGFR L858R and exon 19 deletion mutant patients in 2013. This review focused on current clinical studies of afatinib. Although this TKI was not widely available in China until recently, we aim to provide a reference for its future use in China.

Personalized Radiation Oncology: Epidermal Growth Factor Receptor and Other Receptor Tyrosine Kinase Inhibitors

Molecular biomarkers are currently evaluated in preclinical and clinical studies in order to establish predictors for treatment decisions in radiation oncology. The receptor tyrosine kinases (RTK) are described in the following text. Among them, the most data are available for the epidermal growth factor receptor (EGFR) that plays a major role for prognosis of patients after radiotherapy, but seems also to be involved in mechanisms of radioresistance, specifically in repopulation of tumour cells between radiotherapy fractions. Monoclonal antibodies against the EGFR improve locoregional tumour control and survival when applied during radiotherapy, however, the effects are heterogeneous and biomarkers for patient selection are warranted. Also other RTK´s such as c-Met and IGF-1R seem to play important roles in tumour radioresistance. Beside the potential to select patients for molecular targeting approaches combined with radiotherapy, studies are also needed to evluate radiotherapy adaptation approaches for selected patients, i.e. adaptation of radiation dose, or, more sophisticated, of target volumes.

Insulin-like Growth Factor 1 Receptor Expression in Advanced Non-small-cell Lung Cancer and its Impact on Overall Survival

BACKGROUND

The insulin-like growth factor 1 receptor (IGF1R) expression has been addressed as a potential prognostic marker in non-small-cell lung cancer (NSCLC) in various studies; however, the associations between IGF1R expression and prognosis of advanced NSCLC patients is still controversial. The aim of our observational, cohort study was to evaluate the expression of IGF1R in advanced NSCLC and its prognostic role. A subgroup analysis was performed to address the influence of pre-existing type 2 diabetes mellitus (T2DM) status on IGF1R expression and overall survival (OS).

PATIENTS AND METHODS

IGF1R expression was evaluated in 167 consecutive advanced NSCLC patients (stage IIIB and IV), diagnosed and treated at one university institution, between 2005 and 2010. All patients received at least one line of standard cytotoxic therapy and 18 of them had pre-existing T2DM. IGF1R expression was determined by immunohistochemical (IHC) staining, with score ≥ 1+ considered as positive. Information on baseline characteristics, as well as patients' follow-up data, were obtained from the hospital registry. Associations of IGF1R expression with clinical characteristics and overall survival were compared.

RESULTS

IGF1R expression was positive in 79.6% of patients, significantly more often in squamous-cell carcinoma (SCC) compared to non-squamous-cell (NSCC) histology (88.7% vs. 74.3%; P = 0.03). IGF1R positivity did not correlate with T2DM status or with other clinical features (sex, smoking status, performance status). Median OS was similar between IGF1R positive and IGF1R negative group (10.2 vs. 8.5 months, P = 0.168) and between patients with or without T2DM (8.7 vs. 9.8 months, P = 0.575). Neither IGF1R expression nor T2DM were significant predictors of OS.

CONCLUSIONS

IGF1R or T2DM status were not significantly prognostic in described above collective of advanced NSCLC treated with at least one line of chemotherapy. In addition, no association between T2DM status and IGF1R expression was found. Further studies on IGF1R expression and its prognostic as well as therapeutic consequences in a larger collective of advanced NSCLC patients, with or without T2DM, are needed.

Expressions of insulin-like growth factor receptor-1 and cezanne-1 in lung adenocarcinoma

IGF1R (insulin-like growth factor receptor-1) was confirmed to play a significant role in the development of cancer. Cezanne-1 overexpression was considered to be associated with enhancement of EGFR signaling pathway and reduced degeneration of EGFR. There was a close relationship between EGFR and IGFR as previous study showed. Dynamic balance between receptor ubiquitination and deubiquitination was critical in the process of termination of IGF signaling pathway. So we conducted an IHC staining to initially prove the correlation. Cezanne-1 and IGF1R expressions were evaluated in 103 patients with lung adenocarcinoma using immunohistochemical (IHC) analysis. The relationship between expressions of cezanne-1 and IGF1R were analyzed by χ2 test. Kaplan-Meier method was used to generate the survival curve, and the statistical difference was calculated by log-rank test. We also used data in R2 system to verify the relationship between IGF1R and cezanne-1. R2 system showed there was a close correlation between IGF1R and cezanne-1. Positive expression of cezanne-1 was detected in 64.1% patients. A significant association was shown between cezanne-1 and IGF1R expression (p < 0.001). Multivariate analysis confirmed that both cezanne-1 and IGF1R expressions were independent prognostic factors for OS. (HR 2.96, 95% CI 1.090-8.060, p = 0.033; HR 2.273, 95% CI 1.016-5.085, p = 0.046, respectively). Our findings indicated both cezanne-1 and IGF1R expressions were negative independent predictive factors for the prognosis of lung adenocarcinoma, respectively. There was a close positive interrelationship between cezanne-1 and IGF1R expression.

Cell-Free RNA Content in Peripheral Blood as Potential Biomarkers for Detecting Circulating Tumor Cells in Non-Small Cell Lung Carcinoma

Circulating tumor cells (CTCs) have been implicated in tumor progression and prognosis. Techniques detecting CTCs in the peripheral blood of patients with non-small cell lung carcinoma (NSCLC) may help to identify individuals likely to benefit from early systemic treatment. However, the detection of CTCs with a single marker is challenging, owing to low specificity and sensitivity and due to the heterogeneity and rareness of CTCs. Herein, the probability of cell-free RNA content in the peripheral blood as a potential biomarker for detecting CTCs in cancer patients was investigated. An immunomagnetic enrichment of real-time reverse-transcription PCR (RT-PCR) technology for analysis of CTCs in NSCLC patients was also developed. The mRNA levels of four candidate genes, cytokeratin 7 (CK7), E74-like factor 3 (ELF3), epidermal growth factor receptor (EGFR), and erythropoietin-producing hepatocellular carcinoma receptor B4 (EphB4) that were significantly elevated in tumor tissues and peripheral blood mononuclear cells (PBMCs) were determined. The expression of CK7 and ELF3 in tumor tissues and EGFR in PBMCs was associated with lymph node metastasis (all p < 0.05). The expression of CK7 in PBMCs was correlated with age and EphB4 in PBMCs correlated with histopathological type, respectively (all p < 0.05). The expression of all four genes in tumor tissues and PBMCs was significantly correlated with the clinical stage (all p < 0.01). Survival analysis showed that the patients with enhanced expression of CK7, ELF3, EGFR, and EphB4 mRNA in PBMCs had poorer disease-free survival (DFS) and overall survival (OS) than those without (all p < 0.0001). The present study showed that this alteration of cell-free RNA content in peripheral blood might have clinical ramifications in the diagnosis and treatment of NSCLC patients.

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.

Pathway Targeted Immunotherapy: Rationale and Evidence of Durable Clinical Responses with a Novel, EGF-directed Agent for Advanced NSCLC

Abnormalities in the epidermal growth factor (EGF) and EGFR pathway promote progression of NSCLC. Immunization with EGF vaccine induces specific, neutralizing anti-EGF antibodies that prevent binding of the ligand to its receptor. This concept of pathway targeted immunotherapy (PTI) was validated in vitro by dose-related suppression of EGFR, Akt, and Erk1/2 phosphorylation in cell lines with different mutations. A randomized phase II trial showed improved overall survival (OS) in subgroups with advanced NSCLC showing a clear immunologic response. By per-protocol analysis of the ensuing phase IIb trial, patients receiving EGF PTI survived 3 months longer than controls (12.43 versus 9.43 months; hazard ratio = 0.77 [95% confidence interval, 0.61-0.98]). These data were confirmed in a larger trial showing an OS benefit over control of >3 months. The variable most strongly correlated with efficacy was circulating EGF at enrolment. Patients with serum EGF levels >250 pg/mL benefited most from treatment with EGF PTI. Of 188 patients tested, 94 were above this biomarker threshold. The OS benefit from active versus control treatment was 6.7 months. More than 15% of patients had responses for >5 years. Long-term survivors are seen in all EGF PTI trials. Treatment is well-tolerated, induces high anti-EGF antibody titers, reduces levels of circulating serum EGF, achieves durable responses, and significantly prolongs OS. A threshold of 250 pg/mL has been set to enrich the study population in the ongoing pivotal trial. This biomarker-guided study in an enriched population of patients with both squamous and nonsquamous stage IV NSCLC aims to replicate the favorable efficacy/tolerability balance of earlier studies.

Implications of Insulin-like Growth Factor 1 Receptor Activation in Lung Cancer

Insulin-like growth factor 1 receptor (IGF1R) has been intensively investigated in many preclinical studies using cell lines and animal models, and the results have provided important knowledge to help improve the understanding of cancer biology. IGF1R is highly expressed in patients with lung cancer, and high levels of circulating insulin-like growth factor 1 (IGF1), the main ligand for IGF1R, increases the risk of developing lung malignancy in the future. Several phase I clinical trials have supported the potential use of an IGF1R-targeted strategy for cancer, including lung cancer. However, the negative results from phase III studies need further attention, especially in selecting patients with specific molecular signatures, who will gain benefits from IGF1R inhibitors with minimal side effects. This review will discuss the basic concept of IGF1R in lung cancer biology, such as epithelial-mesenchymal transition (EMT) induction and cancer stem cell (CSC) maintenance, and also the clinical implications of IGF1R for lung cancer patients, such as prognostic value and cancer therapy resistance.

BMS-754807 is cytotoxic to non-small cell lung cancer cells and enhances the effects of platinum chemotherapeutics in the human lung cancer cell line A549

Background

Despite advances in targeted therapy for lung cancer, survival for patients remains poor and lung cancer remains the leading cause of cancer-related deaths worldwide. The type I insulin-like growth factor receptor (IGF-IR) has emerged as a potential target for lung cancer treatment, however, clinical trials to date have provided disappointing results. Further research is needed to identify if certain patients would benefit from IGF-IR targeted therapies and the ideal approach to incorporate IGF-IR targeted agents with current therapies.

Methods

The dual IGF-IR/insulin receptor inhibitor, BMS-754807, was evaluated alone and in combination with platinum-based chemotherapeutics in two human non-small cell lung cancer (NSCLC) cell lines. Cell survival was determined using WST-1 assays and drug interaction was evaluated using Calcusyn software. Proliferation and apoptosis were determined using immunofluorescence for phospho-histone H3 and cleaved caspase 3, respectively.

Results

Treatment with BMS-754807 alone reduced cell survival and wound closure while enhancing apoptosis in both human lung cancer cell lines. These effects appear to be mediated through IGF-IR/IR signaling and, at least in part, through the PI3K/AKT pathway as administration of BMS-754807 to A549 or NCI-H358 cells significantly suppressed IGF-IR/IR and AKT phosphorylation. In addition of BMS-754807 enhanced the cytotoxic effects of carboplatin or cisplatin in a synergistic manner when given simultaneously to A549 cells.

Conclusions

BMS-754807 may be an effective therapeutic agent for the treatment of NSCLC, particularly in lung cancer cells expressing high levels of IGF-IR.

Endometrial Cancer Insulin-Like Growth Factor 1 Receptor (IGF1R) Expression Increases with Body Mass Index and Is Associated with Pathologic Extent and Prognosis

BACKGROUND

Obesity is a main risk factor for endometrial carcinoma (EC). Insulin-like growth factor 1 receptor (IGF1R) expression may influence this association.

METHODS

IGF1R IHC was performed on a tissue microarray with 894 EC and scored according to the percentage and intensity of staining to create immunoreactivity scores, which were dichotomized into low and high IGF1R expression groups. Logistic regression modeling assessed associations with body mass index (BMI), age, histology, pathologic extent of disease (pT), and lymph node metastasis (pN). Overall survival (OS) and disease-free survival (DFS) were compared between IGF1R expression groups using Kaplan-Meier curves and log-rank tests.

RESULTS

The proportion of patients with high IGF1R expression increased as BMI (<30, 30-39, and 40+ kg/m(2)) increased (P = 0.002). The adjusted odds of having high IGF1R expression was 1.49 [95% confidence interval (CI), 1.05-2.10, P = 0.024] for patients with BMI 30 to 39 kg/m(2) compared with <30 kg/m(2) and 1.62 (95% CI, 1.13-2.33, P = 0.009) for patients with BMI 40+ kg/m(2) compared with <30 kg/m(2). High IGF1R expression was associated with pT and pN univariately and with pT after adjusting for BMI, pN, age, and histologic subtype. DFS and OS were better with high IGF1R expression, P = 0.020 and P = 0.002, respectively, but DFS was not significant after adjusting for pT, pN, and histologic subtype of the tumor.

CONCLUSIONS

There is an association between BMI and EC IGF1R expression. Higher IGF1R expression is associated with lower pT and better DFS and OS.

IMPACT

These findings suggest a link between IGF1R EC expression and obesity, as well as IGF1R expression and survival.

Membranous Insulin-like Growth Factor-1 Receptor (IGF1R) Expression Is Predictive of Poor Prognosis in Patients with Epidermal Growth Factor Receptor (EGFR)-Mutant Lung Adenocarcinoma

BACKGROUND

Insulin-like growth factor-1 receptor (IGF1R) is a membrane receptor-type tyrosine kinase that has attracted considerable attention as a potential therapeutic target, although its clinical significance in non-small cell lung cancer (NSCLC) is controversial. This study aimed to clarify the clinical significance of IGF1R expression in human NSCLC.

METHODS

IGF1R protein expression was evaluated using immunohistochemistry in 372 patients with NSCLC who underwent curative surgical resection (146 squamous cell carcinomas [SqCCs] and 226 adenocarcinomas [ADCs]). We then analyzed correlations between expression of IGF1R and clinicopathological and molecular features and prognostic significance.

RESULTS

Membranous and cytoplasmic IGF1R expression were significantly higher in SqCCs than in ADCs. In patients with SqCC, membranous IGF1R expression was associated with absence of vascular, lymphatic, and perineural invasion; lower stage; and better progression-free survival (PFS) (hazard ratio [HR], 0.586; p = .040). In patients with ADC, IGF1R expression did not have a significant prognostic value; however, in the subgroup of epidermal growth factor receptor (EGFR)-mutant ADC, membranous IGF1R expression was associated with lymphatic and perineural invasion, solid predominant histology, and higher cancer stage and was significantly associated with worse PFS (HR, 2.582; p = .009).

CONCLUSIONS

Lung ADC and SqCC showed distinct IGF1R expression profiles that demonstrated prognostic significance. High membranous IGF1R expression was predictive of poor PFS in EGFR-mutant lung ADC, while it was predictive of better PFS in SqCC. These findings will help improve study design for subsequent investigations and select patients for future anti-IGF1R therapy.

Flot-2 Expression Correlates with EGFR Levels and Poor Prognosis in Surgically Resected Non-Small Cell Lung Cancer

We previously reported that expression of Flotillin 2 (Flot-2), a protein isolated from caveolae/lipid raft domains, increased significantly in nasopharyngeal carcinoma (NPC) compared with normal tissues. Signal transduction through epidermal growth factor receptors (EGFR) and Flot-2 play an important role in cancer development, but their precise role in lung cancer has not been investigated. In this study, we have investigated the correlation between the expression of Flot-2 and EGFR, which increase significantly in non-small cell lung cancer (NSCLC) patients (n=352) compared with non-cancer tissues. Additionally, patients with advanced stages of NSCLC had higher positive expression of Flot-2 and EGFR than patients with early stages. NSCLC patients with increased expression of Flot-2 and EGFR had significantly less overall survival rates than patients with less expression of Flot-2 and EGFR. Taken together, our data suggest that increased expression of Flot-2 and EGFR in NSCLC patients is inversely proportional to the disease prognosis and that increased expression of Flot-2 associated with increased EGFR may serve as a biomarker to predict poor disease prognosis.

Mutational analysis of the insulin-like growth factor 1 receptor tyrosine kinase domain in non-small cell lung cancer patients

The insulin-like growth factor 1 receptor (IGF1R) pathway plays an important role in the pathogenesis of non-small cell lung cancer (NSCLC) and also provides a mechanism of resistance to targeted therapies. IGF1R is therefore an ideal therapeutic target and several inhibitors have entered clinical trials. However, thus far the response to these inhibitors has been poor, highlighting the importance of predictive biomarkers to identify patient cohorts who will benefit from these targeted agents. It is well-documented that mutations and/or deletions in the epidermal growth factor receptor (EGFR) tyrosine kinase (TK) domain predict sensitivity of NSCLC patients to EGFR TK inhibitors. Single-nucleotide polymorphisms (SNPs) in the IGF pathway have been associated with disease, including breast and prostate cancer. The aim of the present study was to elucidate whether the IGF1R TK domain harbours SNPs, somatic mutations or deletions in NSCLC patients and correlates the mutation status to patient clinicopathological data and prognosis. Initially 100 NSCLC patients were screened for mutations/deletions in the IGF1R TK domain (exons 16-21) by sequencing analysis. Following the identification of SNP rs2229765, a further 98 NSCLC patients and 866 healthy disease-free control patients were genotyped using an SNP assay. The synonymous SNP (rs2229765) was the only aberrant base change identified in the IGF1R TK domain of 100 NSCLC patients initially analysed. SNP rs2229765 was detected in exon 16 and was found to have no significant association between IGF1R expression and survival. The GA genotype was identified in 53.5 and 49.4% of NSCLC patients and control individuals, respectively. No significant difference was found in the genotype (P=0.5487) or allele (P=0.9082) frequencies between the case and control group. The present findings indicate that in contrast to the EGFR TK domain, the IGF1R TK domain is not frequently mutated in NSCLC patients. The synonymous SNP (rs2229765) had no significant association between IGF1R expression and survival in the cohort of NSCLC patients.

Inhibition of IGF1R signaling abrogates resistance to afatinib (BIBW2992) in EGFR T790M mutant lung cancer cells

Non-small cell lung cancer (NSCLC) patients with an epidermal growth factor receptor (EGFR) mutation have benefited from treatment of reversible EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib. Acquisition of a secondary mutation in EGFR T790M is the most common mechanism of resistance to first generation EGFR TKIs, resulting in therapeutic failure. Afatinib is a second generation of EGFR TKI that showed great efficacy against tumors bearing the EGFR T790M mutation, but it failed to show the improvement on overall survival of lung cancer patients with EGFR mutations possibly because of novel acquired resistance mechanisms. Currently, there are no therapeutic options available for lung cancer patients who develop acquired resistance to afatinib. To identify novel resistance mechanism(s) to afatinib, we developed afatinib resistant cell lines from a parental human-derived NSCLC cell line, H1975, harboring both EGFR L858R and T790M mutations. We found that activation of the insulin-like growth factor 1 receptor (IGF1R) signaling pathway contributes to afatinib resistance in NSCLC cells harboring the T790M mutation. IGF1R knockdown not only significantly sensitizes resistant cells to afatinib, but also induces apoptosis in afatinib resistance cells. In addition, combination treatment with afatinib and linsitinib shows more than additive effects on tumor growth in in vivo H1975 xenograft. Therefore, these finding suggest that IGF1R inhibition or combination of EGFR-IGF1R inhibition strategies would be potential ways to prevent or potentiate the effects of current therapeutic options to lung cancer patients demonstrating resistance to either first or second generation EGFR TKIs.

Expression and clinical significance of epidermal growth factor receptor and insulin-like growth factor receptor 1 in patients with ampullary adenocarcinoma

Epidermal growth factor receptor (EGFR) and insulin-like growth factor receptor 1 (IGF-1R) play important roles in cell proliferation, antiapoptosis, angiogenesis, and metastasis and have been used for targeted therapies for patients with advanced colorectal and lung cancers. However, the expression and function of EGFR and IGF-1R in ampullary adenocarcinoma (AA) have not been examined in detail. We examined the expression of EGFR and IGF-1R in 106 AA patients at our institution using tissue microarrays and immunohistochemistry. The results were correlated with the clinicopathological parameters and survival. Overexpression of EGFR and IGF-1R was detected in 18 (17%) and 26 (25%) of AAs, respectively. Patients with EGFR-high tumors had shorter overall survival (mean, 109.8 ± 22.3 months) than those patients whose tumors were EGFR-low in overall study population (mean, 164.2 ± 10.6 months; P = .04). Overexpression of EGFR correlated with poor overall survival in patients with intestinal-type AA (P = .01) but not in those with pancreaticobiliary-type AAs (P = .47). In multivariate analysis, EGFR overexpression was an independent prognostic factor for overall survival (P = .02). In addition, we found that overexpression of IGF-1R correlated with AAs of pancreaticobiliary histology. No additional correlation between the expression of EGFR or IGF-1R and other clinicopathological factors was observed in our patient population. Our study demonstrates that EGFR and IGF-1R appear to be overexpressed in a subset of AAs and that strong membranous expression of EGFR is an independent predictor for overall survival in patients with AA. EGFR and IGF-1R represent potential therapeutic targets for treatment of patient with AAs.

Rationale for targeting the ErbB family of receptors in patients with advanced squamous cell carcinoma of the lung

Squamous cell carcinoma (SCC) of the lung represents around 30% of all non-small-cell lung cancers. Treatment options for nonsquamous histology have increased in recent years following the development of pemetrexed chemotherapy and the identification of activating EGFR mutations and ALK rearrangements as targets for effective noncytotoxic agents. By contrast, until recently the development of new therapies for SCC has lagged behind. However, the identification of important genetic events driving SCC, including a greater understanding of the role of the ErbB receptor family in SCC pathogenesis, as well as recent immunotherapy advances, have led to new treatment options for SCC.

Tumor-suppressive microRNA-206 as a dual inhibitor of MET and EGFR oncogenic signaling in lung squamous cell carcinoma

Expression of the oncogene hepatocyte growth factor receptor (MET) and phosphorylation of the MET protein have been associated with both primary and acquired resistance to tyrosine kinase inhibitors (TKIs) used in therapy targeting the epidermal growth factor receptor (EGFR) in patients with non-small cell lung cancers (NSCLCs). Therefore, simultaneous inhibition of both of these receptor tyrosine kinases (RTKs) should improve disease treatment. Our previous study of microRNA (miRNA) expression signatures of lung squamous cell carcinoma (lung-SCC) revealed that microRNA-206 (miR‑206) was significantly reduced in lung-SCC tissues, suggesting that miR‑206 functions as a tumor suppressor in the disease. Furthermore, putative miR‑206 binding sites were annotated in the 3'-UTRs of MET and EGFR RTKs in miRNA databases. The aim of the study was to investigate the functional significance of miR‑206 in lung-SCC and to confirm the inhibition of both MET and EGFR oncogenic signaling by expression of miR‑206 in cancer cells. We found that restoration of mature miR‑206 inhibited cancer cell proliferation, migration, and invasion in EBC-1 cells through downregulation of both mRNA and protein levels of MET and EGFR. Interestingly, phosphorylation of ERK1/2 and AKT signaling were inhibited by restoration of miR‑206 in cancer cells. Overexpression of MET and EGFR were observed in clinical specimens of lung-SCC. Tumor-suppressive miR‑206 inhibited dual signaling networks activated by MET and EGFR, and these findings will provide new insights into the novel molecular mechanisms of lung-SCC oncogenesis and new therapeutic approaches for the treatment of this disease.

Let-7b-5p regulates proliferation and apoptosis in multiple myeloma by targeting IGF1R

Multiple myeloma (MM) is the most common cause of death from hematological malignancy worldwide, and recent studies have revealed that let-7b-5p can play an inhibitory role in tumorigenesis. However, the role of let-7b-5p in MM still remains unclear. The aim of this study was to elucidate the molecular mechanisms by which let-7b-5p acts as a tumor suppressor in MM. Here, quantitative real-time polymerase chain reaction results showed that the expression of let-7b-5p was remarkably reduced in MM tissues and MM cell lines (RPMI-8226 and U266 cells). Furthermore, over-expression of let-7b-5p significantly suppressed RPMI-8226 cell proliferation and induced S/G2 cell cycle arrest and apoptosis. Luciferase reporter assay results demonstrated that insulin-like growth factor receptor 1 (IGF1R) was negatively regulated by let-7b-5p at the post-transcriptional level. The mRNA and protein levels of IGF1R in RPMI-8226 cells were down-regulated by let-7b-5p. Furthermore, the cell phenotype altered by let-7b-5p inhibitor can be rescued by IGF1R silencing (si-IGF1R). Taken together, our results demonstrated that let-7b-5p functions as a tumor suppressor in MM, suggesting that let-7b-5p may be a potential therapeutic target for MM.

MiR-195 inhibits the growth and metastasis of NSCLC cells by targeting IGF1R

MicroRNAs (miRNAs) are small, non-coding RNAs which act as oncogenes or tumor suppressors in multiple human cancers. Accumulating evidence reveals that aberrant expression of miRNAs contributes to the development and progression of non-small cell lung cancer (NSCLC). Here, we identified miR-195 as a tumor suppressor in NSCLC cells, whose expression level was dramatically decreased in both NSCLC tissues and cell lines. Ectopic expression of miR-195 suppressed NSCLC cell proliferation and metastasis-related traits in vitro. Insulin-like growth factor 1 receptor (IGF1R) was identified as a direct target of miR-195 in NSCLC cells. Furthermore, restoration of IGF1R remarkably attenuated the tumor suppressive effects of miR-195 on NSCLC cells. Our data suggest that miR-195 may be involved in the carcinogenesis of NSCLC partially by targeting IGF1R.