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BACKGROUND AND AIMS: Epigenetic reprogramming and escape from terminal differentiation are poorly understood enabling characteristics of liver cancer. Keratin 19 (KRT19), classically known to form the intermediate filament cytoskeleton, is a marker of stemness and worse prognosis in liver cancer. This study aimed to address the functional roles of KRT19 in liver tumorigenesis and to elucidate the underlying mechanisms. APPROACH AND RESULTS: Using multiplexed genome editing of hepatocytes in vivo, we demonstrated that KRT19 promoted liver tumorigenesis in mice. Cell fractionation revealed a previously unrecognized nuclear fraction of KRT19. Tandem affinity purification identified histone deacetylase 1 and REST corepressor 1, components of the corepressor of RE-1 silencing transcription factor (CoREST) complex as KRT19-interacting proteins. KRT19 knockout markedly enhanced histone acetylation levels. Mechanistically, KRT19 promotes CoREST complex formation by enhancing histone deacetylase 1 and REST corepressor 1 interaction, thus increasing the deacetylase activity. ChIP-seq revealed hepatocyte-specific genes, such as hepatocyte nuclear factor 4 alpha ( HNF4A ), as direct targets of KRT19-CoREST. In addition, we identified forkhead box P4 as a direct activator of aberrant KRT19 expression in liver cancer. Furthermore, treatment of primary liver tumors and patient-derived xenografts in mice suggest that KRT19 expression has the potential to predict response to histone deacetylase 1 inhibitors especially in combination with lenvatinib. CONCLUSIONS: Our data show that nuclear KRT19 acts as a transcriptional corepressor through promoting the deacetylase activity of the CoREST complex, resulting in dedifferentiation of liver cancer. These findings reveal a previously unrecognized function of KRT19 in directly shaping the epigenetic landscape in cancer.
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OBJECTIVE: To compare clinical results of treatment of Pipkin type I and II femoral head fractures through modified Smith-Peterson(S-P) approach and modified Hardinge approach. METHODS: From July 2005 to July 2014, 42 patients with Pipkin type I and II femoral head fractures were treated with operation. A total of 23 patients in anterior group was treated with modified S-P approach including 17 males and 6 females with an average age of (29.3±9.4) years old, 5 cases of type I by excision of the fragement, 3 cases of type I and 15 cases of type II cases by fixation of the fragement. While a total of 19 patients in the lateral group was treated with modified Hardinge approach including 15 males and 4 females with an average age of (31.4±10.0) years old, 3 cases of type I by excision of the fragement, 4 cases of type I and 12 cases of type II by fixation of the fragement. Operative time, blood loss during operation and fracture healing time were observed and compared. The clinical and radiographic outcomes of the patients were measured using Thompson-Epstein scoring scale. The effect of hip reduction time of less than 6 h, 6 to12 h, and more than 12 h, the effect of surgery time within 24 h and more than 24 h after injury were compared. RESULTS: All patients were followed up from 24 to 60 months with an average of(30.29±6.95) months. The operation time (61.96±12.22) min, blood loss (46.09±18.03) ml, and (74.74±10.06) min, blood loss (72.11±19.88) ml in lateral group in the anterior group were better than those of lateral group(P<0.05). In anterior group, fracture healing time was(12.22±1.70) weeks, the results were excellent in 8 cases, good in 10 cases, fair in 4 cases and poor in 1 case, the excellent and good rate was 78.3%, the incidence of avascular necrosis of femoral head was 8.69%(2/23), and the incidence of heterotopic ossification was 13.04%(3/23). While in lateral group, the fracture healing time was(12.42±1.95) weeks, the results were excellent in 6 cases, good in 7 cases, fair in 3 cases and poor in 3 cases, the excellent and good rate was 68.4%, the incidence of avascular necrosis of femoral head was 10.53%(2/19), and the incidence of heterotopic ossification was 5.26%(1/19). There was no significant difference in fracture healing time, postoperative effect and postoperative complications between the anterior group and lateral group(P<0.05). The effect of patients with reduction time of hip dislocation less than 12 h was significantly better than that of more than 12 h, there was no significant difference in the effect between reduction time within 6 h and 6 to 12 h. There was no significant difference in the outcome between surgical patients within 24 h and more than 24 h after injury. CONCLUSIONS: Dislocated hip of Pipkin type I and II femoral head fractures should be closed reduction within 6 h. If conditions are limited, the reduction time can be accepted within 12 h. Both of modified S-P approach and modified Hardinge approach are effective in treating Pipkin type I and II femoral head fractures, and can obtain excellent outcomes. Moreover, modified S-P approach has advantage of less trauma, less blood loss, shorter operative time.