The effect of forced expression of mutatedK-RASgene on gastrointestinal cancer cell lines and the IGF-1R targeting therapy

Antitumoral RNA-targeted oligonucleotide therapeutics: the third pillar after small molecule inhibitors and antibodies

Oligonucleotide therapeutics, drugs consisting of 10–50 nucleotide‐long single‐ or double‐stranded DNA or RNA molecules that can bind to specific DNA or RNA sequences or proteins, include antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), microRNAs (miRNAs), aptamers, and decoys. These oligonucleotide therapeutics could potentially become the third pillar of drug development. In particular, ASOs and siRNAs are advanced tools that are widely used to silence gene expression. They are used in clinical trials, as they have high specificity for target mRNAs and non‐coding RNAs and limited toxicity. However, their clinical application remains challenging. Although chemotherapy has benefits, it has severe adverse effects in many patients. Therefore, new modalities for targeted molecular therapy against tumors, including oligonucleotide therapeutics, are required, and they should be compatible with diagnosis using next‐generation sequencing. This review provides an overview of the therapeutic uses of ASOs, siRNAs, and miRNAs in clinical studies on malignant tumors. Understanding previous research and development will help in developing novel oligonucleotide therapeutics against malignant tumors.

Circulating insulin-like growth factor binding protein-3 and risk of gastrointestinal malignant tumors

BACKGROUND AND AIM

Insulin-like growth factor-1 (IGF1) is a potent mitogen and is inhibited by IGF-binding protein-3 (IGFBP3). High serum IGF1 and low IGFBP3 are associated with increased risk of several carcinomas. Here, we assessed the relationship of these peptides with the risk of gastrointestinal malignancies, in a prospective case-control study nested in the Japan Collaborative Cohort Study.

METHODS

The analysis involved 916 cases who had been diagnosed as gastrointestinal malignancies (C15-25) and 2306 controls. To estimate odds ratios for incidence of malignancies associated with these levels, a conditional logistic model was used.

RESULTS

Both higher total and free IGFBP3 were associated with a decreased risk of tumor (P for trend < 0.001 and = 0.003, respectively). People in the second to fifth quintiles had lower risk compared to the first quintile (odds ratios ranged 0.532-0.650 and 0.582-0.725, respectively). After adjustment for IGF1, body mass index, drinking, and smoking, total IGFBP3 was inversely correlated with cancer risk (P for trend = 0.031). After adjustment, free IGFBP3 was inversely associated with the risk (P for trend = 0.007). Although total IGF1 was inversely correlated with tumor risk, it was not after controlling for IGFBP3 (P for trend = 0.007 and 0.589, respectively). Free IGF1 was not associated with the risk (P for trend = 0.361). Limiting subjects to those followed for over 3 years reinforced the inverted relationships of total and free IGFBP3 with risk for tumors (P for trend = 0.005 and 0.008, respectively).

CONCLUSION

Both total and free IGFBP3 may be inversely associated with the incidence of gastrointestinal malignancies.

Dual inhibition of IGF-IR and ALK as an effective strategy to eradicate NPM-ALK+ T-cell lymphoma

Background

Nucleophosmin-anaplastic lymphoma kinase-expressing (NPM-ALK⁺) T cell lymphoma is an aggressive neoplasm. NPM-ALK, an oncogenic tyrosine kinase, plays a critical role in this lymphoma. Recently, selective ALK inhibitors have emerged as a first-line therapy for this neoplasm. Unfortunately, ALK inhibitors were hindered by emergence of resistance and relapse. We have previously demonstrated that type I insulin-like growth factor receptor (IGF-IR) is commonly expressed and activated in this lymphoma. In addition, IGF-IR and NPM-ALK are physically associated and reciprocally enhance their phosphorylation/activation. Herein, we tested the hypothesis that combined inhibition of IGF-IR and NPM-ALK could significantly improve the effects of inhibiting each kinase alone.

Methods

We used clinically utilized inhibitors of IGF-IR (picropodophyllin; PPP) and ALK (ASP3026) to assess the in vitro cellular effects of combined treatment versus treatment using a single agent. Moreover, we used a systemic NPM-ALK⁺ T cell lymphoma mouse model to analyze the in vivo effects of PPP and ASP3026 alone or in combination.

Results

Our data show that combined treatment with PPP and ASP3026 decreased the viability, proliferation, and anchorage-independent colony formation, and increased apoptosis of NPM-ALK⁺ T cell lymphoma cells in vitro. The in vitro effects of combined treatment were synergistic and significantly more pronounced than the effects of PPP or ASP3026 alone. Biochemically, simultaneous antagonism of IGF-IR and ALK induced more pronounced decrease in pIGF-IR^Y1135/1136, pNPM-ALK^Y646, and pSTAT3^Y705 levels than antagonizing IGF-IR or ALK alone. Moreover, combined targeting of IGF-IR and NPM-ALK decreased significantly systemic lymphoma tumor growth and improved mice survival in vivo. Consistent with the in vitro results, the in vivo effects of the combined therapy were more pronounced than the effects of targeting IGF-IR or ALK alone.

Conclusions

Combined targeting of IGF-IR and ALK is more effective than targeting IGF-IR or ALK alone in NPM-ALK⁺ T cell lymphoma. This strategy might also limit emergence of resistance to high doses of ALK inhibitors. Therefore, it could represent a successful therapeutic approach to eradicate this aggressive lymphoma. Importantly, combined inhibition is feasible because of the clinical availability of IGF-IR and ALK inhibitors. Our findings are applicable to other types of cancer where IGF-IR and ALK are simultaneously expressed.

Electronic supplementary material

The online version of this article (10.1186/s13045-019-0768-8) contains supplementary material, which is available to authorized users.

IGF-I regulates HT1080 fibrosarcoma cell migration through a syndecan-2/Erk/ezrin signaling axis

Fibrosarcoma is a tumor of mesenchymal origin, originating from fibroblasts. IGF-I is an anabolic growth factor which exhibits significant involvement in cancer progression. In this study, we investigated the possible participation of syndecan-2 (SDC-2), a cell membrane heparan sulfate (HS) proteoglycan on IGF-I dependent fibrosarcoma cell motility. Our results demonstrate that SDC-2-deficient HT1080 cells exhibit attenuated IGF-I-dependent chemotactic migration (p < 0.001). SDC-2 was found to co-localize to IGF-I receptor (IGF-IR) in a manner dependent on IGF-I activity (P ≤ 0.01). In parallel, the downregulation of SDC-2 significantly inhibited both basal and due to IGF-I action ERK1/2 activation, (p < 0.001). The phosphorylation levels of ezrin (Thr567), which is suggested to act as a signaling bridge between the cellular membrane receptors and actin cytoskeleton, were strongly enhanced by IGF-I at both 1h and 24h (p < 0.05; p < 0.01). The formation of an immunoprecipitative complex revealed an association between SDC2 and ezrin which was enhanced through IGF-I action (p < 0.05). Immunoflourescence demonstrated a co-localization of IGF-IR, SDC2 and ezrin upregulated by IGF-I action. IGF-I enhanced actin polymerization and ezrin/actin specific localization to cell membranes. Finally, treatment with IGF-I strongly increased SDC2 expression at both the mRNA and protein level (p < 0.001). Therefore, we propose a novel SDC2-dependent mechanism, where SDC2 is co-localized with IGF-IR and enhances its' IGFI-dependent downstream signaling. SDC2 mediates directly IGFI-induced ERK1/2 activation, it recruits ezrin, contributes to actin polymerization and ezrin/actin specific localization to cell membranes, ultimately facilitating the progression of IGFI-dependent fibrosarcoma cell migration.