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Background: N 6 -methyladenosine (m 6 A) is the most abundant epitranscriptomic modification of RNA, which can affect RNA metabolism and protein translation. The m 6 A modification plays a critical role in cancer development, including hepatocellular carcinoma (HCC). Despite several m 6 A-related signatures in HCC, most of them lack the necessary validation and the reliability is still elusive., Methods: Differentially expressed genes (DEGs) in the Cancer Genome Atlas were comprehensively analyzed to identify m 6 A signature associated with HCC prognosis. Gene set enrichment analysis, tumor mutation burden (TMB), immune infiltration, and therapeutic response were evaluated. Importantly, mass spectrometry proteomics and multiplex immunofluorescence assays were performed for validation., Results: The m 6 A-related protein-coding gene signature was established, which can divide HCC into high-/low-risk subgroups with markedly different overall survival (OS) and clinical stages. Furthermore, we validated its reliability and robustness in our 101 independent HCC specimens using proteomic detection and confirmed that our signature readily identified high-risk HCC patients with 3-year survival rates of 44.1% vs. 71.8% in the low-risk group. Functional analysis indicated that the high-risk group might stimulate the cell cycle and activate oncogenic pathways such as MAPK, mTOR, and VEGF, whereas the low-risk group mainly regulated amino acid, fatty acid, and drug metabolism. Additionally, the high-risk group had more TMB, upregulated immune checkpoint molecule expression, including PD-1, CTLA4, TIM3, and LAG3, and preferentially formed an immunosuppressive microenvironment. Accordingly, potential therapeutic responses showed that high-risk patients were potentially sensitive to inhibitors targeting the cell cycle and MAPK signaling, with patients possibly benefiting from immunotherapy. Moreover, multiplex immunofluorescence assays indicated that high-risk HCC samples displayed distinct immunosuppressive features, with abundant M2-polarized macrophages and T-regulatory cell infiltration., Conclusion: The m 6 A signature had a prominent capacity to evaluate OS and characterize the tumor immune microenvironment of HCC, which may serve as a useful approach for risk stratification management and provide a valuable clue to choosing rational therapeutic strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ma, Li, Shen, Gu, Zhang, Li, Zhao and Wang.)

Cellular senescence, an irreversible growth arrest of cells, is involved in protection against cancer. Triptolide (TPL) plays an important role in immunosuppressive, anti-fertility, anti-cystogenesis and anticancer activities. However, effect and mechanism of TPL on cellular senescence-associated antitumor is rarely reported. Herein HepG2 cells were used to explore the effect of TPL on tumor growth and cellular senescence. We showed that TPL inhibited tumor cell proliferation and growth in vitro and in vivo, accelerated cellular senescence and arrested cells at G0/G1 phase. We further demonstrated that TPL accelerated HepG2 cell senescence by regulating the AKT pathway. In addition, TPL could also enhance cellular senescence and inhibit tumor growth by negatively regulating human telomerase reverse transcriptase (hTERT) signaling pathway. These findings reveal a regulatory mechanism of TPL on cellular senescence, indicating that TPL promotes HepG2 cell senescence through AKT pathway and hTERT pathway simultaneously. Altogether, TPL-induced senescence can be regarded as a promising strategy for anticancer therapy and drug development.

Objective: To summarize the clinical characteristics, early diagnosis, comprehensive treatment and prognosis of 6 cases of children with post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation., Method: Data of 6 cases with PTLD seen between January 2011 and December 2013 were retrospectively analyzed. The anti-rejection drug dose adjustments, the effect of rituximab, antiviral therapy and comprehensive treatment program after surgery were explored., Result: (1) The diagnosis of PTLD was confirmed by histologic findings. Six cases of PTLD including 3 males and 3 females were diagnosed as congenital biliary atresia and underwent split liver transplantation. The occurrence rate of PTLD was 2.9%. (2) The median time to the development of PTLD was less than 6 months. The initial symptom of PTLD in all patients was fever and clinical manifestations of PTLD were non-specific, depending on the involving organs. Five cases of PTLD developed gastrointestinal symptoms, including diarrhea, abdominal pain, and abdominal distension. One case developed respiratory symptoms, including cough and tachypnea. Three cases had lymph node involvement. In 2 cases pathophysiology involved polymorphic lymphocyte proliferation and in 4 cases B lymphocyte proliferation. (3) Two cases died, in whom EBV DNA was not detected and were diagnosed as PTLD by surgical pathology before death. Four survived cases had high EBV-DNA load and then were diagnosed as PTLD by biopsy pathology. (4) Of the 6 cases of PTLD, 2 cases died and 4 cases survived. The overall mortality was 33%. The dead cases were only treated with laparotomy because of intestinal obstruction or perforation and the survived cases were treated with tacrolimus at reduced doses or discontinuation and rituximab. In 2 cases antiviral therapy (acyclovir) was continued, including 1 cases of intestinal obstruction treated with surgical repair. All the survived patients were followed up for 4 months to 1 year and no evidence has been found., Conclusion: EBV infection is the high risk factor for PTLD after liver transplantation. Close clinical surveillance of EBV DNA for pediatric liver transplantation was important for the early diagnosis of PTLD. Reducing doses of immunosuppressive agents and rituximab is the initial therapy for PTLD. A reduction in the dose of tacrolimus is suggested. Operation therapy can also play a role in the management of local complications.