Receptor Tyrosine Kinases in Osteosarcoma: 2019 Update

The primary conclusions of our 2014 contribution to this series were as follows: Multiple receptor tyrosine kinases (RTKs) likely contribute to aggressive phenotypes in osteosarcoma and, therefore, inhibition of multiple RTKs is likely necessary for successful clinical outcomes. Inhibition of multiple RTKs may also be useful to overcome resistance to inhibitors of individual RTKs as well as resistance to conventional chemotherapies. Different combinations of RTKs are likely important in individual patients. AXL, EPHB2, FGFR2, IGF1R, and RET were identified as promising therapeutic targets by our in vitro phosphoproteomic/siRNA screen of 42 RTKs in the highly metastatic LM7 and 143B human osteosarcoma cell lines. This chapter is intended to provide an update on these topics as well as the large number of osteosarcoma clinical studies of inhibitors of multiple tyrosine kinases (multi-TKIs) that were recently published

Supplementary Material for: Adherence and Patients' Attitudes to Oral Anticancer Drugs: A Prospective Series of 201 Patients Focusing on Targeted Therapies

<b><i>Objectives:</i></b> Patient adherence is a challenge in oncology and hematology practice. Hormone therapy data in breast cancer suggest insufficient adherence and poor persistence. Limited data are available for targeted therapies (TT) including tyrosine kinase and mammalian target of rapamycin inhibitors. <b><i>Methods:</i></b> We performed a prospective survey using a 15-item questionnaire in patients with solid tumors and hematologic malignancies receiving oral anticancer therapy. Treatment duration, setting (adjuvant vs. metastatic), cancer type, age, and comedication were recorded. <b><i>Results:</i></b> 201 patients (median age 65.5 years) participated, 102 with TT and 99 with hormone therapy or chemotherapy (HC). The median time of drug intake was 11.0 months. Written information was more frequently given to TT patients (68.6 vs. 23.2%, p < 0.0001). TT and HC patients showed equal adherence to therapy (72.5 vs. 69.6%, p = n.s.) despite TT patients experiencing more side effects (p < 0.0001) and taking more concomitant oral medication (p = 0.0042). Forgotten doses were the leading cause of nonadherence in HC patients (83%, as compared to 54% in the TT group), whereas dose reduction by the patient was higher in the TT group (32 vs. 17%). <b><i>Conclusions:</i></b> Despite advances in providing information to patients leading to better adherence among TT patients, efforts towards better patient education are warranted including dedicated staff for monitoring outpatient anticancer oral therapy

Nuclear insulin-like growth factor-1 receptor (IGF1R) displays proliferative and regulatory activities in non-malignant cells.

The insulin-like growth factor-1 receptor (IGF1R) mediates the biological actions of IGF1 and IGF2. The IGF1R is involved in both physiological and pathological activities and is usually overexpressed in most types of cancer. In addition to its classical mechanism of action, recent evidence has shown a nuclear presence of IGF1R, associated with novel genomic/transcriptional types of activities. The present study was aimed at evaluating the hypothesis that nuclear IGF1R localization is not restricted to cancer cells and might constitute a novel physiologically relevant regulatory mechanism. Our data shows that nuclear translocation takes place in a wide array of cells, including normal diploid fibroblasts. In addition, we provide evidence for a synergistic effect of a nuclear translocation blocker along with selective IGF1R inhibitors in terms of decreasing cell proliferation. Given the important role of the IGF1R in mitogenesis, the present results may be of translational relevance in cancer research. In conclusion, results are consistent with the concept that nuclear IGF1R fulfills important physiological and pathological roles