Sunitinib treatment promotes metastasis of drug-resistant renal cell carcinoma via TFE3 signaling pathway

Luchao Li,Shuo Pang,Yidong Fan,Nianzhao Zhang,Jikai Liu,Zhengfang Liu,Cheng Liu,Shuo Zhao

doi:10.1038/s41419-021-03511-3

Abstract

Receptor tyrosine kinase (RTK) inhibitors, such as sunitinib and sorafenib, remain the first-line drugs for the treatment of mRCC. Acquired drug resistance and metastasis are the main causes of treatment failure. However, in the case of metastasis Renal Cell Cancer (mRCC), which showed a good response to sunitinib, we found that long-term treatment with sunitinib could promote lysosome biosynthesis and exocytosis, thereby triggering the metastasis of RCC. By constructing sunitinib-resistant cell lines in vivo, we confirmed that TFE3 plays a key role in the acquired resistance to sunitinib in RCC. Under the stimulation of sunitinib, TFE3 continued to enter the nucleus, promoting the expression of endoplasmic reticulum (ER) protein E-Syt1. E-Syt1 and the lysosomal membrane protein Syt7 form a heterodimer, which induces ER fragmentation, Ca2+ release, and lysosomal exocytosis. Lysosomal exocytosis has two functions: pumping sunitinib out from the cytoplasm, which promotes resistance to sunitinib in RCC, releasing cathepsin B (CTSB) into the extracellular matrix (ECM), which can degrade the ECM to enhance the invasion and metastasis ability of RCC. Our study found that although sunitinib is an effective drug for the treatment of mRCC, once RCC has acquired resistance to sunitinib, sunitinib treatment will promote metastasis.

Highlights

Renal cell carcinoma (RCC) accounts for approximately2% of all adult malignancies worldwide[1]
Acquired resistance to Receptor tyrosine kinase (RTK) inhibitors and tumor metastasis are the main causes of treatment failure
Most of the studies on transcription factor E3 (TFE3) and cancer focus on Xp11.2 translocation renal cell carcinoma but not Clear cell renal cell carcinoma (ccRCC), a special type of RCC characterized by gene fusions involving TFE3 or Transcription factor EB (TFEB)

Summary

Materials and methods

Samples were obtained with the consent of the ethics committee of Qilu hospital and the patient herself. After the culture medium was removed, post-transfected cells were washed with preheated PBS and counter stained with Hoechst 33342 for 10 min followed by washing in preheated PBS and incubated in preheated culture medium (Life technologies). For ER tracker (Serve Life Science, Shanghai China) staining, after 100 μl working solution incubated with indicated cells for 10 min, post transfected cells were washed with preheated PBS and stained with Hoechst 33342 for 10 min followed by washing in preheated PBS and incubated in preheated culture medium (Life technologies). The 786 O cells stably expressing TFE3 were randomly injected subcutaneously into six nude mice (5 × 106 cells in 200 μl PBS, n = 3/group) at 4 weeks of age. The biggest tumor from each group in the P3 generation was selected for primary cell extraction and culture. P value < 0.05 is considered as statistically significant and are indicated as follows: *P < 0.05; **P < 0.01; ***P < 0.001

Result

Findings

Discussion