Prognostic factors for event-free survival in liver transplantation for hepatoblastoma: A single-center experience

Phase separation of YAP mediated by coiled-coil domain promotes hepatoblastoma proliferation via activation of transcription

AIM AND BACKGROUND

Yes-associated protein (YAP), a key transcriptional co-activator associated with cell fate and tumor progression, has been reported to be a powerful driver of hepatoblastoma (HB). In this study, we investigated the mechanism underlying oncogenic role of YAP in HB.

METHODS

The expression of YAP in HB tissues was measured through WB and qRT-PCR. The IHC and IF were performed to determine the distribution of YAP. The phase separation of YAP was proved by living cell imaging and FRAP experiment. The effect of YAP phase separation in HB cells in vitro an in vivo were tested using CCK8, flow cytometry, and xenograft tumors.

RESULTS

YAP was overexpressed and activated in HB. Nuclear YAP formed an active transcriptional site via LLPS to recruit the crucial transcription factor TEAD4. Thus, YAP phase separation facilitated transcription of oncogenic genes and subsequently mediated chemoresistance of HB. Mechanistically, the phase separation ability of YAP depends on the coiled-coil domain, which is a typical phase separation domain. The electrostatic interactions and hydrophobic interactions within YAP are also vital to YAP phase separation. More importantly, YAP inhibitor verteporfin is potential treatment for HB and combination with cisplatin enhanced therapeutic efficacy.

CONCLUSIONS

Highly expressed and active YAP exerts an oncogenic effect in HB via phase separation and provides new insights for the treatment of HB.

Clinical Characteristics and Prognosis Analysis of Infantile Hepatoblastoma-A 15-Year Retrospective Single-Center Study

Objective

The present study aimed to summarize the clinical data of hepatoblastoma (HB) in infants under one year of age and to analyze the factors that affected the prognoses.

Methods

The clinical data of 132 pediatric patients with a pathologically confirmed HB, aged less than one year and who had visited the Pediatric Single Center of Beijing Tongren Hospital from May 2005 to May 2019, were retrospectively analyzed to summarize the clinical outcomes and prognoses.

Results

The male/female ratio was 1.27 and the median age was 8.40 months. The onset of HB was usually characterized by abdominal bulging (75.0%). The median level of AFP at the first visit was 154.7µg/mL, and the average platelet count was (405±166)×10⁹/L. The epithelial type (57.6%) was the predominant pathological type, and stage III (54.5%) was the main PRETEXT staging. Distant metastases occurred in 45 cases, with pulmonary metastases (86.7%) being the most common site. At the time of visit, 24 cases (18.2%) had either portal vein, hepatic vein, or vena cava infiltration. Five cases (3.8%) had a hemorrhage of the ruptured tumor, and 26 cases (19.7%) had multiple intrahepatic foci. At the follow-up in May 2020, the overall survival (OS) rate at one, three, and five years of age was 94.3%, 88.8%, and 80.1%, respectively, and the event-free survival rate was 91.8%, 86.9%, and 77.5%, respectively, by the Kaplan–Meier survival analysis. According to the Log rank test, pediatric patients with an AFP <100ng/mL, a PRETEXT stage IV, presence of distant metastases and multiple foci of the primary tumor at the initial diagnosis had poorer prognoses (P<0.05).

Conclusion

The prognosis of HB in infancy is relatively good, but is still vulnerable to multiple factors, such as tumor features leading to different AFP levels, PRETEXT stage, presence of distant metastases, and multiple intrahepatic foci.