Serine/threonine kinase TBK1 promotes cholangiocarcinoma progression via direct regulation of ß-catenin.

Cholangiocarcinoma (CCA) is a highly heterogeneous and metastatic malignancy with a poor prognosis even after curative hepatectomy. Studies exploring its pathogenesis and identifying effective therapeutic targets are urgently needed. In this study, we found that TANK-binding kinase 1 (TBK1), a serine/threonine-protein kinase, showed a dynamic increase during the different stages of murine spontaneous CCA carcinogenesis (hyperplasia, dysplasia, and CCA). TBK1 was upregulated in human tissues, including intrahepatic (n = 182) and extrahepatic (n = 40) CCA tissues, compared with nontumor tissues, and the elevated expression of TBK1 was positively correlated with larger tumour diameter, lymph node metastasis, and advanced TNM stage. Functional studies indicated that TBK1 promoted CCA growth and metastasis both in vitro and in vivo. TBK1 directly interacts with ß-catenin, promoting its phosphorylation at the S552 site and its nuclear translocation, which further activates EMT-related transcriptional reprogramming. GSK-8612, a TBK1 inhibitor or a kinase-inactivating mutation, effectively suppresses the above processes. In addition, we found that low-density lipoprotein receptor (LDLR), which mediates the endocytosis of cholesterol, was upregulated in CCA. Therefore, we designed a cholesterol-conjugated DNA/RNA heteroduplex oligonucleotide targeting TBK1 (Cho-TBK1-HDO), which could accumulate in CCA cells via LDLR, reduce the TBK1 mRNA level and inhibit intrahepatic metastasis of CCA. Besides, in the experimental group of 182 ICC patients, high TBK1 expression combined with high nuclear ß-catenin expression predicted a worse prognosis. In summary, TBK1 might serve as a potential prognostic biomarker and therapeutic target for patients with CCA.

Surgical outcomes and survival for T4 gastric cancer extending to the transverse colon.

BACKGROUND: For the treatment of locally advanced (T4) gastric cancer, extended multi-organ resection remains controversial. This study aimed to evaluate the surgical outcomes and survival of patients with T4 gastric cancer extending to the transverse colon. METHODS: A total of 2,652 gastric cancer patients underwent surgery between December 2011 and December 2015. Data from 40 of these patients who underwent curative resection for T4 gastric cancer extending to the transverse colon were obtained. Patient characteristics, related complications, long-term survival, and prognostic factors for T4 gastric cancer were analyzed. RESULTS: Postoperative morbidity occurred in 5 (12.5%) patients. All of the patients were cured with conservative treatment. No procedure-related mortality occurred. The 1-, 3-, and 5-year overall survival (OS) rates were 75.0%, 49.2%, and 36.9%, respectively, with a median survival time of 24 months. Univariate analysis revealed tumor size (P=0.049), advanced T stage (P=0.013), and lymph node metastasis (P=0.006) to be poor prognostic factors of OS. Advanced T stage and lymph node metastasis were identified by multivariate analysis as being independent prognostic factors. Further, it was observed that lymph node metastasis grade was associated with poorer OS. CONCLUSIONS: Patients with T4 gastric cancer extending to the transverse colon might benefit from curative resection with acceptable morbidity and mortality.