Hepatocellular carcinoma (HCC) is a formidable adversary in the landscape of global health, with its high recurrence rate being a major contributor to the poor prognosis and elevated mortality rates among patients. Despite the utility of laboratory markers like alpha-fetoprotein (AFP) and imaging techniques in diagnosing recurrence, the early detection of this phenomenon remains elusive6–8. This study, therefore, aimed to identify predictive biomarkers that could foresee recurrences in HCC, a pursuit that is both timely and crucial.
The genesis of tumors is a complex tapestry woven by multiple genetic alterations, and while the molecular underpinnings of HCC's initiation and progression are not fully elucidated, certain mutations stand out. TP53 mutations and TERT promoter mutations are reported to be the most common somatic alterations in hepatocellular carcinoma7,9–16. Notably, TERTpm have been linked to enhanced telomerase activity and TERT mRNA expression across various cancers, including meningioma, urothelial carcinoma, glioblastoma, and HCC. These alterations are associated with cellular immortalization and a grim prognosis10,27,35–37. TP53 mutations, in turn, often result in the inactivation of TP53 and p53 protein, leading to chromosomal instability and unchecked proliferation, hallmarks of many cancers38,39. However, the interplay between TERTpm and TP53 mutations and their collective impact on HCC recurrence is not well understood, a gap this study sought to bridge.
For this reason, using the next-generation sequencing technology, we identified the genetic landscape and mutation signatures of HCC in liver tumor tissues from 50 HCC patients. The association of TP53m, TERTpm, and their coexistence with clinicopathological features and outcome was explored to further clarify their potential value in HCC.
We identified that all tumor tissues involved in this study harbored genetic alterations, among which TP53m and TERTpm (C228T) were the most frequent, with a prevalence of 48% and 32%, respectively. Previous published studies showed that the incidence of TP53m and TERTpm (C228T) in HCC were 18.7%~48% and 14.9%~60%, respectively7,9–16. Overall, our results were consistent with those of most previous findings, indicating the importance of TP53m and TERTpm (C228T) in HCC. After that, other mutated genes such as LRP1B (26%), CTNNB1 (18%) and AXIN1 (14%) were also identified in the present study, which were similar to the previous researches10,13,29,40,41. Our results showed that patients with TP53m were significantly associated with moderately differentiated tumors and early recurrence. Meanwhile, TERTpm were considerably associated with male gender and lower serum AFP levels. However, neither TP53m nor TERTpm was linked to age, body measurements, tumor characteristics, or other clinical features and laboratory features, suggesting a more nuanced relationship between these genetic alterations and clinical manifestations..
Among the 50 HCC patients, 23 cases experienced intrahepatic tumor recurrence or distant metastases, 9 harbored TP53m alone, 3 harbored TERTpm alone, 6 harbored both, and 5 harbored neither. According to these data, we can infer that patients with TP53 mutations were more likely to experience tumor recurrence than negative ones. While the recurrence rate of HCC in patients with TERTpm was not statistically different from those TERTpm-negative ones, the presence of TERTpm did elevate the probability of tumor recurrence in patients from 41.2–56.3%, especially the early recurrence rate was improved from 23.5–43.8%. However, there was no significant difference of recurrence rate in patients with neither TP53m alone nor TERTpm alone, compared to those with negative TP53m and negative TERTpm. By contrast, coexistence of TERTpm and TP53m indicated a higher likelihood of tumor recurrence, and poor progression-free survival. This finding is intriguing, as it points to a potential synergistic effect between these mutations, a hypothesis supported by the known interaction between p53 and TERT.
Previous studies have found a strong interaction between p53 and TERT. On the one hand, p53 as a transcription factor have been shown to repress TERT mRNA level 42,43. On the other hand, suppression of TERT could induce DNA damage and apoptosis in a p53-dependent way44–46. Further, both TERTpm and TP53m are associated with tumorigenesis. Thus, we speculated that genomic mutations of both TERT and TP53 have strengthened the interaction between the two, which promote tumor progression and lead to poorer prognosis in HCC patients.
To address this hypothesis, we consulted the current literature on p53-TERT and found that p53 was a powerful inhibitor of the TERT promoter activity. TP53m were responsible for upregulation of TERT mRNA level, by physically interacting with other transcription factors such as Sp1 (activate transcription of TERT) to nucleated onto the TERT promoter47–49. Since TERTpm could introduce new binding sites for transcription factors such as ETS/TCF, and TERT promoter also contain Sp1 binding motifs. Taken together, it is thus overwhelmingly probable that TERTpm C228T may introduce a new binding site for Sp1, facilitating increased p53 binding and TERT activation. However, further work is required to investigate the exact mechanisms and their functional effects, since there is a lack of evidence at this point to support our hypothesis.
In conclusion, this study provides a comprehensive genomic portrait of HCC, identifying TP53m and TERTpm as common somatic alterations. The coexistence of these mutations appears to be a promising marker for tumor recurrence and poor prognosis, offering valuable insights for postoperative surveillance and personalized treatment strategies. While our findings are promising, they also underscore the need for larger-scale studies to validate these observations and explore the underlying mechanisms, potentially paving the way for novel therapeutic interventions in HCC.