Expressional and functional characteristics of checkpoint kinase 1 as a prognostic biomarker in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is the most common pathological subtype of liver cancer and is the third leading cause of cancer death worldwide. Checkpoint kinase 1 (CHEK1), an essential serine/threonine kinase that regulates the cell cycle, is reported to be associated with carcinogenesis. However, the biological role and clinical significance of CHEK1 in HCC are still incompletely known. Methods: In this research, CHEK1 messenger RNA (mRNA) levels in various liver hepatocellular carcinoma (LIHC) cohorts from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were evaluated. The Kaplan-Meier database was applied to identify the correlation between survival time and CHEK1 expression in patients with HCC. Gene set enrichment analysis (GSEA) was performed to explore the potential mechanism of CHEK1 in HCC, and NetworkAnalyst v. 3.0 (https://www.networkanalyst.ca/) was used to construct the regulatory networks of CHEK1 in HCC. Discriminant Regulon Expression Analysis (DoRothEA) was used to detect the activity of transcriptional factors (TFs) in gene-enriched cells (EC) with CHEK1 coexpression. In vitro experiments were conducted to investigate the effects of CHEK1 on the biological function of HCC cells. Results: The CHEK1 mRNA level was overexpressed in HCC, and increased CHEK1 expression correlated with poor survival outcomes. The homo sapiens-microRNA-195 (hsa-miR-195) may have contributed to the upregulation of CHEK1 in HCC. GSEA and NetworkAnalyst v. 3.0 showed that CHEK1 played a crucial part in tumor proliferation of HCC and may be regulated by TF E2F1. DoRothEA showed increased transcriptional activity of E2F1 in gene-EC with CHEK1 coexpression. Moreover, experiments of cell function showed that the knockdown of CHEK1 weakened the aggressive behavior and proliferation of HCC cells. Overexpression of E2F1 increased the proliferation and invasion of HCC cells in vitro, while the silencing of CHEK1 dampened cell invasion induced by E2F1 overexpression. Conclusions: These results identified the prognostic significance and expression characteristics of CHEK1 in HCC through bioinformatics analysis and experimental verification. This lays the foundation for further research on the diagnosis and treatment of HCC.

CAPS1 Suppresses Tumorigenesis in Cholangiocarcinoma.

BACKGROUND: CAPS1 (calcium-dependent activator protein for secretion) is a multi-domain protein involved in regulating exocytosis of synaptic vesicles and dense-core vesicles. However, the expression and function of CAPS1 in cholangiocarcinoma (CCA) remains unclear. In the present study, we explored the role of CAPS1 in CCA carcinogenesis. METHODS: CAPS1 expression was explored using western blotting and immunohistochemistry in four CCA cell lines and clinical samples from 90 cases of CCA. The clinical significance of CAPS1 was analyzed. The biological function of CAPS1 in CCA cells was detected in vitro and in vivo. The underlying mechanism of CAPS1 function was explored by detecting the expression of critical molecules in its associated signaling pathways. The mechanism of CAPS1 downregulation in tumor tissues was explored using in silico prediction and luciferase reporter assays. RESULTS: CAPS1 expression was reduced in CCA cell lines and human tumor tissues. Loss of CAPS1 in tumor tissues was closely associated with poor prognosis of patients with CCA. Moreover, CAPS1 expression correlated significantly with tumor-node-metastasis stage, lymph node metastasis, and vascular invasion. Lentivirus-mediated CAPS1 overexpression substantially prevented clone formation, cell proliferation, and cell cycle progression. CAPS1 overexpression also suppressed carcinogenesis in nude mice. Mechanistically, CAPS1 overexpression greatly accelerated the ERK and p38 MAPK signal pathways. In addition, microRNA miR-30e-5p negatively regulated CAPS1 expression. CONCLUSION: These data showed that CAPS1 functions as a tumor suppressor in CCA. Reduced CAPS1 expression could indicate poor prognosis of patients with CCA.

L61H46 shows potent efficacy against human pancreatic cancer through inhibiting STAT3 pathway.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer-related death worldwide. The poor prognosis of this disease highlights the urgent need to develop more effective therapies. Activation of the STAT3 represents a potential drug target for pancreatic cancer therapy. Currently, clinically available small-molecule inhibitors targeting STAT3 are lacking. METHODS: Through bioassay screening and molecular docking, we identified a small molecule L61H46 that can potently target constitutive STAT3 signaling and kill human pancreatic cancer cells in vitro and in vivo. RESULTS: L61H46 effectively reduced colony formation and the viability of pancreatic cancer cells in a dose-dependent manner with half-maximal inhibitory concentration (IC50) values in the range between 0.86 and 2.83 µM. L61H46 significantly inhibited STAT3 phosphorylation (Tyr705) and the subsequent nucleus translocation but did not downregulate STAT1 phosphorylation. Moreover, L61H46 demonstrated a potent activity in suppressing pancreatic tumor growth in BXPC-3 xenograft model in vivo. Furthermore, L61H46 showed no signs of adverse effects on liver, heart, and kidney cells in vivo. CONCLUSION: Collectively, our results suggest that L61H46 could be further optimized into a highly potent STAT3 inhibitor for the treatment of pancreatic cancer.

Synthesis and anti-tumor activity of EF24 analogues as IKKß inhibitors.

EF24 is an IKKß inhibitor (IC50: 72 µM) containing various anti-tumor activities. In this study, a series of EF24 analogs targeting IKKß were designed and synthesized. Several IKKß inhibitors with better activities than EF24 were screened out and B3 showed best IKKß inhibitory (IC50: 6.6 µM). Molecular docking and dynamic simulation experiments further confirmed this inhibitory effect. B3 obviously suppressed the viability of Hela229, A549, SGC-7901 and MGC-803 cells. Then, in SGC-7901 and MGC-803 cells, B3 blocked the NF-κB signal pathway by inhibiting IKKß phosphorylation, and followed arrested the cell cycle at G2/M phase by suppressing the Cyclin B1 and Cdc2 p34 expression, induced the cell apoptosis by down-regulating Bcl-2 protein and up-regulating cleaved-caspase3. Moreover, B3 significantly reduced tumor growth and suppressed the IKKß-NF-κB signal pathway in SGC-7901 xenograft model. In total, this study present a potential IKKß inhibitor as anti-tumor precursor.

A novel non-ATP competitive FGFR1 inhibitor with therapeutic potential on gastric cancer through inhibition of cell proliferation, survival and migration.

Fibroblast growth factor receptor 1 (FGFR1), belonging to receptor tyrosine kinases (RTKs), possesses various biological functions. Over-expression of FGFR1 has been observed in multiple human malignancies. Hence, targeting FGFR1 is an attractive prospect for the advancement of cancer treatment options. Here, we present a novel small molecular FGFR1 inhibitor L16H50, which can inhibit FGFR1 kinase in an ATP-independent manner. It potently inhibits FGFR1-mediated signaling in a gastric cancer cell line, resulting in inhibition of cell growth, survival and migration. It also displays an outstanding anti-tumor activity in a gastric cancer xenograft tumor model by targeting FGFR1 signaling. These results show that L16H50 is a potent non-ATP-competitive FGFR1 inhibitor and may provide strong rationale for its evaluation in gastric cancer patients.

Curcumin sensitizes human gastric cancer cells to 5-fluorouracil through inhibition of the NFκB survival-signaling pathway.

Fluorouracil (5-FU) is the most commonly used chemotherapeutic agent for gastric cancer (GC). However, the occurrence of resistance to 5-FU treatment poses a major problem for its clinical efficacy. In this study, we found that the NFκB-signaling pathway can mediate 5-FU resistance in GC cells. We developed a 5-FU-resistant GC cell line named SGCR/5-FU and found that the 5-FU-induced resistance increased cytosolic IκBα degradation and promoted NFκB nuclear translocation in GC cells. These findings were further confirmed by the activation of the NFκB survival-signaling pathway in clinical specimens. Curcumin, a natural compound, can reverse 5-FU resistance and inhibits proliferation in GC cells by downregulating the NFκB-signaling pathway. Moreover, it can also decrease the expression level of TNFα messenger RNA. Flow cytometry and Western blot analysis results showed that the combination of curcumin and 5-FU caused synergistic inhibition of growth and induction of potent apoptosis in the resistant cancer cell lines in vitro. In conclusion, our results demonstrate that the combination of 5-FU and curcumin could be further developed as a potential therapy for human GC.