Cellular retinol binding protein-1 inhibits cancer stemness via upregulating WIF1 to suppress Wnt/ß-catenin pathway in hepatocellular carcinoma.

BACKGROUND: CRBP-1, a cytosolic chaperone of vitamin A, is identified in a serious number of cancers; however, its biological role in hepatocellular carcinoma (HCC) needs to be further explored. The aim of our present study is to explore the roles and mechanisms of CRBP-1 in regulating liver cancer by using in vitro and in vivo biology approaches. METHODS: The expression level of CRBP-1 was detected using immunohistochemistry in HCC and matching adjacent non-tumorous liver tissues. Following established stable CRBP-1 overexpressed HCC cell lines, the cell growth and tumorigenicity were investigated both in vitro and in vivo. Intracellular retinoic acid was quantified by ELISA. The relationship between CRBP-1 and WIF1 was validated by using dual luciferase and ChIP analyses. RESULTS: The low expression of CRBP-1 was observed in HCC tissues compared to the normal liver tissues, while high CRBP-1 expression correlated with clinicopathological characteristics and increased overall survival in HCC patients. Overexpression of CRBP-1 significantly inhibited cell growth and tumorigenicity both in vitro and in vivo. Moreover, overexpression of CRBP-1 suppressed tumorsphere formation and cancer stemness related genes expression in HCC. Mechanically, CRBP-1 inhibited Wnt/ß-catenin signaling pathway to suppress cancer cell stemness of HCC. Furthermore, our results revealed that CRBP-1 could increase the intracellular levels of retinoic acid, which induced the activation of RARs/RXRs leading to the transcriptional expression of WIF1, a secreted antagonist of the Wnt/ß-catenin signaling pathway, by physically interacting with the region on WIF1 promoter. CONCLUSION: Our findings reveal that CRBP-1 is a crucial player in the initiation and progression of HCC, which provide a novel independent prognostic biomarker and therapeutic target for the diagnosis and treatment of HCC.

An oral 2-hydroxypropyl-ß-cyclodextrin-loaded spirooxindole-pyrrolizidine derivative restores p53 activity via targeting MDM2 and JNK1/2 in hepatocellular carcinoma.

Validation of a small molecular compound targeting the oncogenic pathways is the primary approach for the development of the anti-cancer drugs. In the present study, we employed the computational mimic drug targets prediction software to foresee the molecular targets of a series of spirooxindole-pyrrolizidine derivatives, which were synthesized by our laboratory viatargeted combinational chemistry. We found that CPHSP, a novel spirooxindole-pyrrolizidine derivative, can target the MDM2/p53 signaling that is essential for the tumorigenesis of hepatocellular carcinoma (HCC). To validate its anti-tumoral function, we firstly established the soluble receipt of CPHSP through 2-hydroxypropyl-ß-cyclodextrin (HBC) loading and showed that oral administration of HBC-loaded CPHSP significantly inhibited the tumor growth and prolonged the survival time of tumor-bearing mice in the subcutaneously human hepatoma cells-xenografted nude mouse model of HCC. Immunohistochemistry staining showed that HBC-loaded CPHSP treatment suppressed the proliferation and induced apoptosis of tumor cells in this model. Our mechanistic studies showed that CPHSP treatment inhibited MDM2 protein expression and up-regulated p53 activity and activated MKK4/MKK7/JNK1/2/C-Jun signaling pathway, which resulted in cell cycle arrest and apoptosis of HepG2 cells in vitro. Moreover, we showed that JNK1/2 activation could also up-regulate p53 expression in CPHSP-treated HepG2 cells. Finally, we documented the antitumor activities of oral administration of the HBC-loaded CPHSP in the ML-1 bearing orthotopic mouse model. In summary, this study suggests that oral administration of HBC-loaded CPHSP is a safe and effective treatment for HCC, of which the clinical potency for patients with HCC warrants further studies.

Anti-malarial atovaquone exhibits anti-tumor effects by inducing DNA damage in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and is the third most frequent cause of cancer-related deaths worldwide. The development of safe new anti-tumor agents has become increasingly important due to the steady rise in drug-resistant tumors. After assessing the efficacy of several candidate compounds that could inhibit hepatocellular carcinoma, we focused on atovaquone, an FDA-approved anti-malarial drug. In the present study, we found that atovaquone significantly inhibited hepatoma cell proliferation via S phase cell cycle arrest and both extrinsic and intrinsic apoptotic pathway induction associated with upregulation of p53 and p21. Molecular investigations demonstrated that atovaquone inhibits hepatoma cell proliferation by inducing double-stranded DNA breaks, leading to sustained activation of ataxia-telangiectasia mutated (ATM) and its downstream molecules such as cell cycle checkpoint kinase-2 (CHK2) and H2AX. In addition, we found that atovaquone also induced apoptosis, inhibited both cell proliferation and angiogenesis in vivo, and prolonged the survival time of tumor-bearing mice, without any obvious side effects. In conclusion, our data indicate that atovaquone is a safe and effective candidate drug that could be rapidly repurposed for HCC treatment.

JNK1/2 and ERK1/2 provides vital clues about tumor recurrence and survival in hepatocellular carcinoma patients.

AIM: To explore JNK1/2 and ERK1/2 activation in hepatocellular carcinoma (HCC) patients. PATIENTS & METHODS: Phosphorylated-JNK1/2 and -ERK1/2 (p-JNK1/2 and p-ERK1/2) expressions were determined and analyzed in 104 unique HCC tissue specimens. RESULTS: Expression of p-JNK1/2 and p-ERK1/2 was not correlated with clinicopathological characteristics. High p-JNK1/2 and low p-ERK1/2 expressions predicated significantly lower tumor recurrence for HCC patients. However, HCC patients with low p-JNK1/2 and high p-ERK1/2 had higher tumor recurrence. Moreover, p-JNK1/2 positively, but p-ERK1/2 negatively, associated with overall survival (OS) and recurrence-free survival (RFS) in HCC patients. In addition, HCC patients with simultaneous low p-JNK1/2 and high p-ERK1/2 had poorer OS and RFS. On the contrary, patients with high p-JNK1/2 and low p-ERK1/2 presented better OS and RFS. CONCLUSION: HCC patients with low p-JNK1/2 and high p-ERK1/2 either independently or simultaneously, had significantly higher tumor recurrence and worse OS.

ACP5: Its Structure, Distribution, Regulation and Novel Functions.

BACKGROUND: Tartrate-resistant acid phosphatase 5 (ACP5) is an evolutionarily conserved and multifunctional protein that is involved in generations of reactive oxygen species, normal bone development, osteoblast regulation and macrophage function, affecting a series of pathways, as well as reflecting bone resorption and osteoclast activity. METHODS: Literature searches, systematic reviews and assessments about the structure, distribution, regulation and novel functions of ACP5 were performed in this review from PubMed and Medline databases. RESULTS: Studies demonstrate that RANKL can increase the expression of ACP5 through NFATc1 and c-Fos to accelerate osteoclastogenesis, which also can be regulated by many regulators. Based on the aforementioned information, it is shown that ACP5, together with the phosphatase activity, can medicate the progression and development of human genetic diseases and cancer. CONCLUSION: As a novel target, ACP5 plays a critical role in preventing, monitoring and treating various kinds of tumors, as well as accelerating the development of a promising therapeutic strategy for human genetic diseases. However, the explicit mechanism between ACP5 and cancer is not so clear. It is necessary and significant for us to pay more in-depth attention.