Liver X receptors constrain tumor development and metastasis dissemination in PTEN-deficient prostate cancer

Mechanisms of long non-coding RNAs in biological phenotypes and ferroptosis of glioma

Glioma, one of the most common malignant tumors in the nervous system, is characterized by limited treatment, high mortality and poor prognosis. Numerous studies have shown that lncRNAs play an important role in the onset and progression of glioma by acting on various classical signaling pathways of tumors through signaling, trapping, guiding, scaffolding and other functions. LncRNAs contribute to the malignant progression of glioma via proliferation, apoptosis, epithelial-mesenchymal transformation, chemotherapy resistance, ferroptosis and other biological traits. In this paper, relevant lncRNA signaling pathways involved in glioma progression were systematically evaluated, with emphasis placed on the specific molecular mechanism of lncRNAs in the process of ferroptosis, in order to provide a theoretical basis for the application of lncRNAs in the anticancer treatment of glioma.

Liver X receptor agonist T0901317 inhibits the migration and invasion of non-small-cell lung cancer cells in vivo and in vitro

Liver X receptors are recognized as important regulators of cholesterol, fatty acid metabolism, inflammatory responses, and glucose homeostasis. The antineoplastic properties of synthetic liver X receptor (LXR) agonists (T0901317 and GW3965) have been reported in human carcinomas. Epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI) is a first-line treatment for non-small-cell lung cancer patients with EGFR mutations. We used scratch and transwell assays to analyze cell migration and invasion. We evaluated tumor migration and invasion in vitro using a fluorescent orthotopic lung cancer model. An MMP9 (mouse) enzyme-linked immunosorbent assay kit was used to measure serum MMP9 concentrations. Protein expression was identified by western blot assays. In this study, we determined the effects of T0901317 and/or an EGFR-TKI on the lung cancer cell lines A549 and HCC827-8-1 in vitro and in vivo. We confirmed that the combination of the LXR agonist T0901317 and gefitinib can inhibit the migration and invasion of lung cancer both in vivo and in vitro, and this effect was possibly achieved by the inhibition of the ERK/MAPK signaling pathway. Our study showed that the combination of the LXR agonist T0901317 and gefitinib can inhibit the migration and invasion of lung cancer both in vivo and in vitro.

Liver X Receptor Agonism Sensitizes a Subset of Hepatocellular Carcinoma to Sorafenib by Dual-Inhibiting MET and EGFR

Sorafenib is the first approved systemic therapy for advanced hepatocellular carcinoma (HCC) and is the first-line choice in clinic. Sustained activation of receptor tyrosine kinases (RTKs) is associated with low efficacy of sorafenib in HCC. Activation of liver X receptor (LXR) has been reported to inhibit some RTKs. In this study, we found that the LXR agonist enhanced the anti-tumor activity of sorafenib in a subset of HCC cells with high LXR-β/α gene expression ratio. Mechanically, the activation of LXR suppressed sorafenib dependent recruitment of MET and epidermal growth factor receptor (EGFR) in lipid rafts through cholesterol efflux. Our findings imply that LXR agonist can serve as a potential sensitizer to enhance the anti-tumor effect of sorafenib.

Association of PTEN expression with liver function and inflammatory changes in patients with liver cancer after chemotherapy

This study investigated the effects of phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression on liver function classification, serum tumor markers and liver function of patients with liver cancer. A total of 63 patients with primary liver cancer treated in Xiangya Hospital (Changsha, China) were retrospectively analyzed. The difference in the PTEN expression levels in normal liver cells and liver cancer cells was compared via immunohistochemistry. According to the expression level of PTEN in the patient's pathological report, patients were divided into PTEN-positive and PTEN-negative groups. The expression level of each tumor marker in serum of patients was observed, and the association of PTEN expression level with the serum tumor markers was analyzed. Moreover, the changes in liver function and inflammatory factors before and after chemotherapy were compared. Finally, the relationship between the PTEN expression level and Child-Pugh grading of the liver function was detected. Compared with that in normal liver cells, the positive expression rate of PTEN protein in liver cancer cells was significantly decreased (P<0.05). No significant difference was found in the expression levels of serum tumor markers, except α-fetoprotein (AFP) in liver cancer patients between PTEN-positive and PTEN-negative group, indicating that PTEN expression has no significant effects on serum tumor markers. The levels of albumin (ALB), alkaline phosphatase (ALP) and prothrombin activity (PTA) were decreased significantly after chemotherapy compared with those before chemotherapy (P<0.05). Besides, the levels of inflammatory factors were remarkably reduced after chemotherapy. PTEN expression was negatively associated with liver function grading, and the higher the PTEN expression, the lower the liver function grading was. The low expression of PTEN has a certain association with the occurrence and grading of liver cancer. PTEN gene has guiding significance in predicting the occurrence, development and prognosis of liver cancer.

Efatutazone and T0901317 exert synergistically therapeutic effects in acquired gefitinib-resistant lung adenocarcinoma cells

The development of acquired EGFR‐TKI therapeutic resistance is still a serious clinical problem in the management of lung adenocarcinoma. Peroxisome proliferator activated receptor gamma (PPARγ) agonists may exhibit anti‐tumor activity by transactivating genes which are closely associated with cell proliferation, apoptosis, and differentiation. However, it remains not clear whether efatutazone has similar roles in lung adenocarcinoma cells of gefitinib resistant such as HCC827‐GR and PC9‐GR. It has been demonstrated by us that efatutazone prominently increased the mRNA and protein expression of PPARγ, liver X receptor alpha (LXRα),as well as ATP binding cassette subfamily A member 1 (ABCA1). In the presence of GW9662 (a specific antagonist of PPARγ) or GGPP (a specific antagonist of LXRα), efatutazone (40 μmol/L) restored the proliferation of both HCC827‐GR and PC9‐GR cells and obviously inhibited the increased protein and mRNA expression of PPAR‐gamma, LXR‐alpha, and ABCA1 induced by efatutazone. LXRα knockdown by siRNA (si‐LXRα) significantly promoted the HCC827‐GR and PC9‐GR cells proliferation, whereas incubation efatutazone with si‐LXRα restored the proliferation ability compared with the control group. In addition, combination of efatutazone and LXRα agonist T0901317 showed a synergistic therapeutic effect on lung adenocarcinoma cell proliferation and PPAR gamma, LXR A and ABCA1 protein expression. These results indicate that efatutazone could inhibit the cells proliferation of HCC827‐GR and PC9‐GR through PPARγ/LXRα/ABCA1 pathway, and synergistic therapeutic effect is achieved when combined with T0901317.