SALL4 is a CRL3REN/KCTD11 substrate that drives Sonic Hedgehog-dependent medulloblastoma

The Sonic Hedgehog (SHH) pathway is crucial regulator of embryonic development and stemness. Its alteration leads to medulloblastoma (MB), the most common malignant pediatric brain tumor. The SHH-MB subgroup is the best genetically characterized, however the molecular mechanisms responsible for its pathogenesis are not fully understood and therapeutic benefits are still limited. Here, we show that the pro-oncogenic stemness regulator Spalt-like transcriptional factor 4 (SALL4) is re-expressed in mouse SHH-MB models, and its high levels correlate with worse overall survival in SHH-MB patients. Proteomic analysis revealed that SALL4 interacts with REN/KCTD11 (here REN), a substrate receptor subunit of the Cullin3-RING ubiquitin ligase complex (CRL3REN) and a tumor suppressor lost in ~30% of human SHH-MBs. We demonstrate that CRL3REN induces polyubiquitylation and degradation of wild type SALL4, but not of a SALL4 mutant lacking zinc finger cluster 1 domain (ΔZFC1). Interestingly, SALL4 binds GLI1 and cooperates with HDAC1 to potentiate GLI1 deacetylation and transcriptional activity. Notably, inhibition of SALL4 suppresses SHH-MB growth both in murine and patient-derived xenograft models. Our findings identify SALL4 as a CRL3REN substrate and a promising therapeutic target in SHH-dependent cancers

Peroxisome proliferator-activated receptor gamma and spermidine/spermine N(1)-acetyltransferase gene expressions are significantly correlated in human colorectal cancer

BACKGROUND: The peroxisome proliferator-activated receptor γ (PPARγ) is a transcription factor that regulates adipogenic differentiation and glucose homeostasis. Spermidine/spermine N(1)-acetyltransferase (SSAT) and ornithine decarboxylase (ODC) are key enzymes involved in the metabolism of polyamines, compounds that play an important role in cell proliferation. While the PPARγ role in tumour growth has not been clearly defined, the involvement of the altered polyamine metabolism in colorectal carcinogenesis has been established. In this direction, we have evaluated the PPARγ expression and its relationship with polyamine metabolism in tissue samples from 40 patients operated because of colorectal carcinoma. Since it is known that the functional role of K-ras mutation in colorectal tumorigenesis is associated with cell growth and differentiation, polyamine metabolism and the PPARγ expression were also investigated in terms of K-ras mutation. METHODS: PPARγ, ODC and SSAT mRNA levels were evaluated by reverse transcriptase and real-time PCR. Polyamines were quantified by high performance liquid chromatography (HPLC). ODC and SSAT activity were measured by a radiometric technique. RESULTS: PPARγ expression, as well as SSAT and ODC mRNA levels were significantly higher in cancer as compared to normal mucosa. Tumour samples also showed significantly higher polyamine levels and ODC and SSAT activities in comparison to normal samples. A significant and positive correlation between PPARγ and the SSAT gene expression was observed in both normal and neoplastic tissue (r = 0.73, p < 0.0001; r = 0.65, p < 0.0001, respectively). Moreover, gene expression, polyamine levels and enzymatic activities were increased in colorectal carcinoma samples expressing K-ras mutation as compared to non mutated K-ras samples. CONCLUSION: In conclusion, our data demonstrated a close relationship between PPARγ and SSAT in human colorectal cancer and this could represent an attempt to decrease polyamine levels and to reduce cell growth and tumour development. Therefore, pharmacological activation of PPARγ and/or induction of SSAT may represent a therapeutic or preventive strategy for treating colorectal cancer

Influence of clinically significant portal hypertension on survival after hepatic resection for hepatocellular carcinoma in cirrhotic patients

BACKGROUND: The role of clinically significant portal hypertension on the prognosis of cirrhotic patients undergoing hepatic resection for hepatocellular carcinoma (HCC) is debated. AIMS: In this study, our aim was to assess the role of clinically significant portal hypertension after hepatic resection for HCC in patients with cirrhosis. METHODS: We assessed the prognostic role of the presence of clinically significant portal hypertension (oesophageal/gastric varices/portal hypertensive gastropathy or a platelet count <100 7 10(9) /L associated with splenomegaly) in 152 patients with compensated cirrhosis who underwent hepatic resection for HCC at the Italian Liver Cancer centres. Survival rates were assessed in the whole series, in the subgroup of Child-Pugh score 5 patients with uninodular HCC 64 5 cm, and in Child-Pugh score 5 patients with uninodular HCC 64 2 cm and normal bilirubin. RESULTS: Median survival was similar in patients with and without clinically significant portal hypertension (79 vs 77 months, P = 0.686). Child-Pugh score 5 was the only variable significantly associated with survival by Cox multiple regression (P = 0.007). In Child-Pugh score 5 patients with single HCC 64 5 cm or in those with single HCC 64 2 cm and normal bilirubin, there was no survival difference between patients with and without clinically significant portal hypertension (median survival: 94 vs 78 months, P = 0.121 and >100 vs 86 months, P = 0.742). CONCLUSIONS: Presence of clinically significant portal hypertension has no influence on survival of patients with well-compensated cirrhosis undergoing hepatic resection for HCC

Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network

Background: Few data are available on the virological and clinical outcomes of advanced liver disease patients retreated after first-line DAA failure. Aim: To evaluate DAA failure incidence and the retreatment clinical impact in patients treated in the advanced liver disease stage. Methods: Data on HCV genotype, liver disease severity, and first and second line DAA regimens were prospectively collected in consecutive patients who reached the 12-week post-treatment and retreatment evaluations from January 2015 to December 2016 in 23 of the PITER network centers. Results: Among 3,830 patients with advanced fibrosis (F3) or cirrhosis, 139 (3.6%) failed to achieve SVR. Genotype 3, bilirubin levels >1.5mg/dl, platelet count <120,000/mm3 and the sofosbuvir+ribavirin regimen were independent predictors of failure by logistic regression analysis. The failure rate was 7.6% for patients treated with regimens that are no longer recommended or considered suboptimal (sofosbuvir+ribavirin or simeprevir+sofosbuvir\uc2\ub1ribavirin), whereas 1.4% for regimens containing sofosbuvir combined with daclatasvir or ledipasvir or other DAAs. Of the patients who failed to achieve SVR, 72 (51.8%) were retreated with a second DAA regimen, specifically 38 (52.7%) with sofosbuvir+daclatasvir, 27 (37.5%) with sofosbuvir+ledipasvir, and 7 (9.7%) with other DAAs \uc2\ub1ribavirin. Among these, 69 (96%) patients achieved SVR12 and 3 (4%) failed. During a median time of 6 months (range: 5\ue2\u80\u9314 months) between failure and the second DAA therapy, the Child-Pugh class worsened in 12 (16.7%) patients: from A to B in 10 patients (19.6%) and from B to C in 2 patients (10.5%), whereas it did not change in the remaining 60 patients. Following the retreatment SVR12 (median time of 6 months; range: 3\ue2\u80\u9312 months), the Child-Pugh class improved in 17 (23.6%) patients: from B to A in 14 (19.4%) patients, from C to A in 1 patient (1.4%) and from C to B in 2 (2.9%) patients; it remained unchanged in 53 patients (73.6%) and worsened in 2 (2.8%) patients. Of patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. Conclusions: Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication

Modifications of liver disease stage following DAA treatment in patients with cirrhosis.

<p>(A) Baseline, post-failure and post-retreatment SVR12 changes of Child Pugh Class; (B) baseline and post-failure changes of Child Pugh Class for patients who were not retreated yet; (C) baseline and post-SVR12 changes of Child Pugh Class for patients who achieved SVR12 following the first DAA treatment. Bold arrows indicate patients who did not change the Child Pugh Class. Dashed arrows indicate patients who worsened the Child Pugh Class, whereas the grey arrows indicate patients who improved the Child Pugh class. In the curly brackets are reported the number of patients for specific changes observed in the Child Pugh classes in the three points of evaluation. n = number of patients.</p

Failure rates following the first DAA regimen, by HCV genotype and treatment regimen in patients who completed the 12 weeks post treatment evaluation (n = 3,830 patients).

<p>Failure rates following the first DAA regimen, by HCV genotype and treatment regimen in patients who completed the 12 weeks post treatment evaluation (n = 3,830 patients).</p

Univariate and logistic regression analysis linking failure with independent variables.

<p>Univariate and logistic regression analysis linking failure with independent variables.</p