Comprehensive mRNA-based screen for tyrosine kinase fusions and a de novo alternative transcription initiation site in soft tissue sarcomas

Date 24 November 2018
Event ESMO Asia 2018 Congress
Session Poster display - Cocktail
Topics Anticancer Agents
Soft Tissue Sarcomas
Translational Research
Presenter Yoshiyuki Suehara
Citation Annals of Oncology (2018) 29 (suppl_9): ix124-ix128. 10.1093/annonc/mdy443
Authors Y. Suehara1, S. Kohsaka2, A. Kurisaki3, K. Akaike1, T. Hayashi3, K. Mogushi4, T. Okubo1, Y. Kim1, S. Sato5, E. Kobayashi6, K. Kaneko1, H. Mano2, T. Saito3
  • 1Department Of Orthopedic Surgery, Juntendo University School of Medicine, 113-8421 - Tokyo/JP
  • 2Division Of Cellular Signaling, National Cancer Center Research Institute, 1040045 - Tokyo/JP
  • 3Department Of Human Pathology, Juntendo University School of Medicine, 113-8421 - Tokyo/JP
  • 4Center For Genomic And Regenerative Medicine, Juntendo University School of Medicine, 113-8421 - Tokyo/JP
  • 5Department Of Physiology And Cell Biology, Tokyo Medical and Dental University Graduate School and Faculty of Medicine, 113-8510 - Tokyo/JP
  • 6Division Of Orthopedic Oncology, National Cancer Center Hospital, 1040045 - Tokyo/JP

Abstract

Background

Soft tissue sarcomas (STSs) are a heterogeneous group of rare malignant tumors. Systemic chemotherapy consisting cytotoxic Anticancer Agents for STS contributes on improving prognosis of STS treatment. However, advanced STSs have still poor prognosis and effective systemic therapies have not yet been established. Therefore, the identification of novel therapeutic targets and novel effective therapies are required. Receptor tyrosine kinases (RTKs) are being increasingly used as therapeutic targets for a variety of cancers, especially RTK fusion genes. A recent report found that the novel TK transcript initiates from a de novo alternative transcription initiation (ATI) site, especially in ALK (Wiesner T et al. Nature 2015). In addition, the TK-ATI has a novel mechanism of oncogene activation in cancer and TK inhibitors could suppress the kinase activity of TK-ATI. Based on these background, we conducted TK screening using NanoString to identify rational therapeutic TK targets including TK-fusions and TK-ATIs in STSs.

Methods

We studied 24 patients (15 leiomyosarcomas 5 MPNSTs, and 4 high grade myxofibrosarcomas) with STSs. To identify TK-fusions and TK-ATIs, a NanoString-based assay was designed to query the transcripts of 90 tyrosine kinases at two points: 5' to the KD and within the KD or 3' to it. Tumor RNAs were hybridized to the NanoString probes and analyzed for outlier 3' to 5' expression ratios. Presumed novel fusion and ATI events were studied for the positive cases by RNA-seq and confirmatory reverse transcriptase PCR (RT-PCR).

Results

We identified one of aberrant 3' to 5' ratios in ROS1. RNA-seq isolated a novel ROS1 fusion gene, and confirmed by RT-PCR. The case with ROS1rearrangement was a leiomyosarcoma in the thigh from a 90 year old-female. We could not find any TK-ATIs in this cohort.

Conclusions

We conducted TK screening to identify new therapeutic targets in STSs. We found a novel ROS1 fusion as a candidate of therapeutic targets. This study suggested that this screening system might contribute to identify particularly useful therapeutic options for STSs.

Editorial acknowledgement

This study was supported by Grant-in-Aid from the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant Number #15H04964, #16K15670, and #15KK0353 to Y.S. ; #17K08730 to T.S.; #17K10987to K.K.; 17H07098 to K.A.; #16K20070 to T.O.; #18K16634 to Y.M.) and Leading Advanced Projects for Medical Innovation (LEAP) (Grant Number # JP17am0001009 JP18am0001009) and the Practical Research for Innovative Cancer Control (Grant Number # JP18ck0106252) from the Japan Agency for Medical Research and Development.

Clinical trial identification

None

Legal entity responsible for the study

The Ethics Committee of Juntendo University approved this study.

Funding

This study was supported by Grant-in-Aid from the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant Number #15H04964, #16K15670, and #15KK0353 to Y.S.; #17K08730 to T.S.; #17K10987to K.K.; 17H07098 to K.A.; #16K20070 to T.O.; # 18K16634 to Y.M.) and Leading Advanced Projects for Medical Innovation (LEAP) (Grant Number # JP18am0001009) and the Practical Research for Innovative Cancer Control (Grant Number # JP18ck0106252) from the Japan Agency for Medical Research and Development.

Disclosure

All authors have declared no conflicts of interest.