Tianhong Su1,2, Manling Huang3, Junbin Liao1, Shuibin Lin4, Peng Yu4, Jianhua Yang5, Yuhong Cai1, Shenghua Zhu3, Lixia Xu2,6, Zhenwei Peng7,8, Sui Peng2,3,7, Shuling Chen9, Ming Kuang1,2,10. 1. Department of Liver Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 2. Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 3. Department of Gastroenterology and Hepatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 4. Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 5. MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 6. Department of Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 7. Clinical Trials Unit, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. 8. Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. 9. Division of Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. 10. Cancer Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
Abstract
BACKGROUND AND AIMS: The dynamic N6-methyladenosine (m6 A) mRNA modification is essential for acute stress response and cancer progression. Sublethal heat stress from insufficient radiofrequency ablation (IRFA) has been confirmed to promote HCC progression; however, whether m6 A machinery is involved in IRFA-induced HCC recurrence remains open for study. APPROACH AND RESULTS: Using an IRFA HCC orthotopic mouse model, we detected a higher level of m6 A reader YTH N6-methyladenosine RNA binding protein 1-3 (YTHDF1) in the sublethal-heat-exposed transitional zone close to the ablation center than that in the farther area. In addition, we validated the increased m6 A modification and elevated YTHDF1 protein level in sublethal-heat-treated HCC cell lines, HCC patient-derived xenograft (PDX) mouse model, and patients' HCC tissues. Functionally, gain-of-function/loss-of-function assays showed that YTHDF1 promotes HCC cell viability and metastasis. Knockdown of YTHDF1 drastically restrains the tumor metastasis evoked by sublethal heat treatment in tail vein injection lung metastasis and orthotopic HCC mouse models. Mechanistically, we found that sublethal heat treatment increases epidermal factor growth receptor (EGFR) m6 A modification in the vicinity of the 5' untranslated region and promotes its binding with YTHDF1, which enhances the translation of EGFR mRNA. The sublethal-heat-induced up-regulation of EGFR level was further confirmed in the IRFA HCC PDX mouse model and patients' tissues. Combination of YTHDF1 silencing and EGFR inhibition suppressed the malignancies of HCC cells synergically. CONCLUSIONS: The m6 A-YTHDF1-EGFR axis promotes HCC progression after IRFA, supporting the rationale for targeting m6 A machinery combined with EGFR inhibitors to suppress HCC metastasis after RFA.
BACKGROUND AND AIMS: The dynamic N6-methyladenosine (m6 A) mRNA modification is essential for acute stress response and cancer progression. Sublethal heat stress from insufficient radiofrequency ablation (IRFA) has been confirmed to promote HCC progression; however, whether m6 A machinery is involved in IRFA-induced HCC recurrence remains open for study. APPROACH AND RESULTS: Using an IRFA HCC orthotopic mouse model, we detected a higher level of m6 A reader YTH N6-methyladenosine RNA binding protein 1-3 (YTHDF1) in the sublethal-heat-exposed transitional zone close to the ablation center than that in the farther area. In addition, we validated the increased m6 A modification and elevated YTHDF1 protein level in sublethal-heat-treated HCC cell lines, HCC patient-derived xenograft (PDX) mouse model, and patients' HCC tissues. Functionally, gain-of-function/loss-of-function assays showed that YTHDF1 promotes HCC cell viability and metastasis. Knockdown of YTHDF1 drastically restrains the tumor metastasis evoked by sublethal heat treatment in tail vein injection lung metastasis and orthotopic HCC mouse models. Mechanistically, we found that sublethal heat treatment increases epidermal factor growth receptor (EGFR) m6 A modification in the vicinity of the 5' untranslated region and promotes its binding with YTHDF1, which enhances the translation of EGFR mRNA. The sublethal-heat-induced up-regulation of EGFR level was further confirmed in the IRFA HCC PDX mouse model and patients' tissues. Combination of YTHDF1 silencing and EGFR inhibition suppressed the malignancies of HCC cells synergically. CONCLUSIONS: The m6 A-YTHDF1-EGFR axis promotes HCC progression after IRFA, supporting the rationale for targeting m6 A machinery combined with EGFR inhibitors to suppress HCC metastasis after RFA.