Crizotinib-induced antitumour activity in human alveolar rhabdomyosarcoma cells is not solely dependent on ALK and MET inhibition

BACKGROUND: Rhabdomyosarcoma (RMS) is the most commonly diagnosed malignant soft tissue tumour in children and adolescents. Aberrant expression of Anaplastic Lymphoma Kinase (ALK) and MET gene has been implicated in the malignant progression of RMS, especially in the alveolar subtype. This observation suggests that crizotinib (PF-02341066), a kinase inhibitor against ALK and MET, may have a therapeutic role in RMS, although its antitumour activity in this malignancy has not yet been studied. METHODS: RH4 and RH30 alveolar RMS (ARMS) cell lines were treated with crizotinib and then assessed by using proliferation, viability, migration and colony formation assays. Multiple approaches, including flow cytometry, immunofluorescence, western blotting and siRNA-based knock-down, were used in order to investigate possible molecular mechanisms linked to crizotinib activity. RESULTS: In vitro treatment with crizotinib inhibited ALK and MET proteins, as well as Insulin-like Growth Factor 1 Receptor (IGF1R), with a concomitant robust dephosphorylation of AKT and ERK, two downstream kinases involved in RMS cell proliferation and survival. Exposure to crizotinib impaired cell growth, and accumulation at G2/M phase was attributed to an altered expression and activation of checkpoint regulators, such as Cyclin B1 and Cdc2. Crizotinib was able to induce apoptosis and autophagy in a dose-dependent manner, as shown by caspase-3 activation/PARP proteolytic cleavage down-regulation and by LC3 activation/p62 down-regulation, respectively. The accumulation of reactive oxygen species (ROS) seemed to contribute to crizotinib effects in RH4 and RH30 cells. Moreover, crizotinib-treated RH4 and RH30 cells exhibited a decreased migratory/invasive capacity and clonogenic potential. CONCLUSIONS: These results provide a further insight into the molecular mechanisms affected by crizotinib in ARMS cells inferring that it could be a useful therapeutic tool in ARMS cancer treatment

Early and late effects of pharmacological ALK inhibition on the neuroblastoma transcriptome

Background: Neuroblastoma is an aggressive childhood malignancy of the sympathetic nervous system. Despite multi-modal therapy, survival of high-risk patients remains disappointingly low, underscoring the need for novel treatment strategies. The discovery of ALK activating mutations opened the way to precision treatment in a subset of these patients. Previously, we investigated the transcriptional effects of pharmacological ALK inhibition on neuroblastoma cell lines, six hours after TAE684 administration, resulting in the 77-gene ALK signature, which was shown to gradually decrease from 120 minutes after TAE684 treatment, to gain deeper insight into the molecular effects of oncogenic ALK signaling. Aim: Here, we further dissected the transcriptional dynamic profiles of neuroblastoma cells upon TAE684 treatment in a detailed timeframe of ten minutes up to six hours after inhibition, in order to identify additional early targets for combination treatment. Results: We observed an unexpected initial upregulation of positively regulated MYCN target genes following subsequent downregulation of overall MYCN activity. In addition, we identified adrenomedullin (ADM), previously shown to be implicated in sunitinib resistance, as the earliest response gene upon ALK inhibition. Conclusions: We describe the early and late effects of ALK inhibitor TAE684 treatment on the neuroblastoma transcriptome. The observed unexpected upregulation of ADM warrants further investigation in relation to putative ALK resistance in neuroblastoma patients currently undergoing ALK inhibitor treatment

Induction of MET Receptor Tyrosine Kinase Down-Regulation through Antibody-Mediated Receptor Clustering

The proto-oncoprotein MET is a receptor tyrosine kinase that plays a key role in cancer cell growth and invasion. We have used fluorescence-tagged antibodies to activate MET in live serum-starved glioblastoma cells and monitor the fate of antibody-bound MET receptor in single cell-based assays. We found that the antibodies induced rapid and transient formation of highly polarized MET clusters on the plasma membrane and promoted the activation of MET, resembling the initial effects of binding to its ligand, HGF. However, the antibody-induced clustering and activation of MET led to the rapid removal of the receptor from cell surface and altered its intracellular processing, resulted in rapid degradation of the receptor. Consequently, while cells pre-treated with HGF remain competent to respond to further HGF stimulation, cells pre-treated with antibodies are refractory to further HGF stimulation due to antibody-mediated MET depletion. Removal of MET by sustained treatment of antibodies blocked cancer cell migration and invasion. Our studies reveal a novel mechanism to alter the recycling process of MET in glioblastoma cancer cells by promoting the receptor degradation through a proteasome-sensitive and lysosome-dependent pathway through the ligand-independent activation of MET using anti-MET antibodies

Precision oncology: the intention-to-treat analysis fallacy.

It has recently been suggested that precision oncology studies should be reanalysed using the intention-to-treat (ITT) methodology developed for randomized controlled clinical trials. This reanalysis dramatically decreases response rates in precision medicine studies. We contend that the ITT analysis of precision oncology trials is invalid. The ITT methodology was developed three decades ago to mitigate the problems of randomized trials, which try to ensure that both arms have an unselected patient population free from confounders. In contrast, precision oncology trials specifically select patients for confounders (that is biomarkers) that predict response. To demonstrate the issues inherent in an ITT reanalysis for precision cancer medicine studies, we take as an example the drug larotrectinib (TRK inhibitor) approved because of remarkable responses in malignancies harbouring NTRK fusions. Based on large-scale studies, NTRK fusions are found in ~0.31% of tumours. In a non-randomized pivotal study of larotrectinib, 75% of the 55 treated patients responded. Based upon the prevalence of NTRK fusions, ~18,000 patients would need to be screened to enrol the 55 treated patients. Utilizing the ITT methodology, the revised response rate to larotrectinib would be 0.23%. This is, of course, a dramatic underestimation of the efficacy of this now Food and Drug Administration (FDA)-approved drug. Similar issues can be shown for virtually any biomarker-based precision clinical trial. Therefore, retrofitting the ITT analysis developed for unselected patient populations in randomized trials yields misleading conclusions in precision medicine studies

Relationship of Driver Oncogenes to Long-Term Pemetrexed Response in Non--Small-Cell Lung Cancer.

BackgroundPemetrexed is approved in the treatment of advanced stage nonsquamous non-small-cell lung cancer (NSCLC). The length of response is variable, and we thus sought to identify which clinicopathologic characteristics are associated with long-term disease control with pemetrexed.Patients and methodsPatients with metastatic NSCLC received pemetrexed (with or without bevacizumab) for 12 months or longer, either as maintenance treatment after first-line platinum-based chemotherapy or as subsequent treatment. Clinical and pathologic characteristics were collected.ResultsOf a total of 196 patients who received pemetrexed starting in 2007, 25 patients were identified who received pemetrexed for over 1 year. Of these, 15 patients received pemetrexed with or without bevacizumab as maintenance treatment and 10 patients received pemetrexed as subsequent treatment. Fifteen (60%) of 25 patients had an oncogenic driver mutation as follows: 5 (20%) had ROS1 gene rearrangements, 4 (16%) had ALK gene rearrangements, 3 (12%) had KRAS mutations, 2 (8%) had epidermal growth factor receptor (EGFR) mutations, and 1 (4%) had an NRAS mutation. The median overall survival was 42.2 months (95% confidence interval, 37.4-61.3) and median progression-free survival was 22.1 months (95% confidence interval, 15.1-29.1). Patients with an oncogenic driver mutation had significantly better progression-free survival (P = .006) and overall survival (P = .001).ConclusionAmong patients with NSCLC who received pemetrexed for an extended time, those with ALK and ROS1 gene rearrangements were proportionally overrepresented compared with that anticipated in a general nonsquamous NSCLC population, and patients with oncogenic driver mutations had improved outcomes

Successful role of adjuvant radiotherapy in a rare case of tracheal inflammatory myofibroblastic tumor: a case report

BACKGROUND:: Inflammatory myofibroblastic tumor (IMT) is a rare benign cancer that can express a more aggressive phenotype related to the genetic mutation of the anaplastic lymphoma kinase receptor (ALK). Involvement of trachea is extremely rare and due to the clinical and radiologic nonspecificity, the definitive diagnosis is based on the histologic evaluation of tissue specimens. Total surgical excision is curative and chemotherapy or radiotherapy has been employed in the treatment of unresectable tumors or as adjuvant therapies. CASE PRESENTATION:: The case described here is being reported because of the rare tracheal location and the atypical treatment approach used for an ALK-positive IMT. A 7-week pregnant woman voluntary interrupted pregnancy and underwent total surgical excision that resulted to have close margins. Although ALK-positive expression indicated the use of ALK inhibitors, she refused any type of adjuvant therapy that could affect ovarian function. Thus, 3D conformational external beam radiotherapy was performed with a daily dose of 180 cGy, 5 times per week, up to 45 Gy at the level of trachea. A total of 62 months of follow-up showed and no signs of disease recurrence or late radiation therapy-related toxicity. CONCLUSIONS: This report describes an extremely rare case of a tracheal IMT, underlying the key role of radiotherapy as adjuvant treatment able to definitively cure IMT, limiting systemic chemotherapy-related toxicity