Glaucocalyxin A suppresses multiple myeloma progression in vitro and in vivo through inhibiting the activation of STAT3 signaling pathway

Background Multiple myeloma (MM) is the most common malignant hematological disease in the people worldwide. Glaucocalyxin A (GLA) is a bioactive ent-kauranoid diterpenoid, that is derived from Rabdosia japonica var. GLA has been demonstrated that it had various pharmacological activities, such as anti-coagulation, anti-bacterial, anti-tumor, anti-inflammation, antioxidant activities. Although GLA has effective anti-tumor properties, its effects on multiple myeloma remain unclear. The aim of this study was to examine the possible anti-cancer effects of GLA and their molecular mechanisms on MM cells in vitro and in vivo. Methods To evaluate the role of GLA on the proliferation of MM cells in vitro and in vivo, we used MTT method to detect the role of GLA on the proliferation of MM cells. Cell apoptosis and cell cycle assay were evaluated by flow cytometry. Protein expressions in GLA-treated and untreated MM cells were evaluated by western blot analyses. MM xenograft nude mice model was used to investigate the role of GLA on the proliferation of MM cells in vivo. IHC assay was used to examine the role of GLA on the MM xenograft model in vivo. Results In the present study, we firstly reported the potent anti-myeloma activity of GLA on MM cells. We found that GLA could induce apoptosis in vitro and in vivo. GLA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) and downregulate interleukin IL-6 induced STAT3 phosphorylation in MM. Overexpression of STAT3 could significantly prevent apoptosis induced by GLA; while knockdown of STAT3 enhanced it. Moreover, GLA could inhibit cell proliferation by inducing the cell cycle arrest. GLA reduced the expression of cell cycle-related proteins CCNB1, CCND1, CCND2, and CCND3 and increased the expression of p21 in MM cell lines. In addition, in the MM xenograft nude mice model, GLA exhibited very good anti-myeloma activity. Administration of GLA almost completely inhibited tumor growth within 19 days without physical toxicity. And the IHC results showed GLA significantly inhibited cell proliferation and interfered STAT3 pathway on MM xenograft model tumor tissues. Conclusions Taken together, our present research indicated that GLA inhibits the MM cell proliferation, induces MM cell apoptosis and cell cycle arrest through blocking the activation of STAT3 pathway. Thus, GLA may be a potential therapeutic candidate for MM patients in the future.

Acteoside as a potential therapeutic option for primary hepatocellular carcinoma: a preclinical study

Background Hepatocellular carcinoma (HCC) is a common malignant tumor with characteristics of poor prognosis, high morbidity and mortality worldwide. In particular, only a few systemic treatment options are available for advanced HCC patients, and include sorafenib and the recently described atezolizumab plus bevacizumab regimen as possible first-line treatments. We here propose acteoside, a phenylethanoid glycoside widely distributed in many medicinal plants as a potential candidate against advanced HCC. Methods Cell proliferation, colony formation and migration were analyzed in the three human HCC cell lines BEL7404, HLF and JHH-7. Angiogenesis assay was performed using HUVESs. The BEL7404 or JHH-7 xenograft nude mice model was established to analyze the possible antitumor effects of acteoside. qRT-PCR and western blotting were used to reveal the potential antitumor mechanisms of acteoside. Results Acteoside inhibited cell proliferation, colony formation and migration in all the three human HCC cell lines BEL7404, HLF and JHH-7. The prohibition of angiogenesis by acteoside was revealed by the inhibition of tube formation and cell migration of HUVECs. The combination of acteoside and sorafenib produced stronger inhibition of cell colony formation and migration of the HCC cells as well as of angiogenesis of HUVECs. The in vivo antitumor efficacy of acteoside was further demonstrated in BEL7404 or JHH-7 xenograft nude mice model, with an enhancement when combined with sorafenib in inhibiting the growth of JHH-7 xenograft. Further treatment of JHH-7 cells with acteoside revealed an increase in the level of tumor suppressor protein p53 as well as a decrease of kallikrein-related peptidase (KLK1, 2, 4, 9 and 10) gene level with no significant changes of the rest of KLK1–15 genes. Conclusions Acteoside exerts an antitumor effect possibly through its up-regulation of p53 levels as well as inhibition of KLK expression and angiogenesis. Acteoside could be useful as an adjunct in the treatment of advanced HCC in the clinic.

LncRNA BANCR Facilitates Melanoma Cells Growth, Migration and Invasion by Inhibiting miR-206 and miR-571 to Induce G6PD Expression

Background Here, we evaluated the roles of LncRNA BANCR in facilitating melanoma cells growth, migration, invasion. Moreover, we examined the molecular mechanisms of BANCR in promoting melanoma development.Methods Here, we measured BANCR expression by quantitative PCR. By transwell assay, we detected the cancer cell migration and invasion. The melanoma growth and migration induced by BANCR was detected by colony formation assay and in xenograft nude mice model. By Western blotting and luciferase assay, we evaluated the molecular mechanism of BANCR in inhibiting miR-206 and miR-571 to induce G6PD expression. Results We found BANCR was overexpressed in melanoma cells and tissues. In addition, we showed that BANCR promoted melanoma cells growth in vitro and in vivo. Moreover, BANCR promotes cancer cell migration and invasion in vitro, and induced melanoma metastasis in nude mice model. The migration and invasion induced by BANCR in melanoma cells were involved in upregulation of matrix metalloproteinases (MMPs) MMP2 and MMP9. Mechanismly, we indicated BANCR promoted melanoma cell growth and migration by suppressing miR-206 and miR-571 expression to activate glucose metabolism pathway and induce G6PD expression. Furthermore, miR-206 and miR-571 inhibited G6PD expression by directly binding the 3’UTR of G6PD. We also showed miR-206 and miR-571 inhibited the proliferation of melanoma cells.Conclusion Our findings indicated that BANCR contributed to melanoma development, which might provide novel insights into the function of lncRNA-driven carcinogenesis in melanoma.

Lotus Leaf Extract Inhibits the Cell Migration and Metastasis of ER- Breast Cancer

Background: Patients with estrogen receptor negative (ER-) breast cancer have poor prognosis because of their high rates of metastasis. However, there is no effective treatment and drugs for ER− breast cancer metastasis. Our purpose of this study was to evaluate the effect and mechanism of lotus leaf alcohol extract (LAE) on the cell migration and metastasis of ER- breast cancer.Methods: The anti-migratory effect and mechanism of LAE were analysed in ER- breast cancer cells including SK-BR-3, MDA-MB-231 and HCC1806. Cell viability assay, wound-healing assay, RNA-sequence analysis and immunoblotting assay were applied in examining the cytotoxicity, anti-migratory effect and its possible pathways of LAE. To further investigate the inhibitory effect of LAE on metastasis in vivo, subcutaneous xenograft nude mice model and intravenous injection nude mice model were established. Lung and liver tissues were analysed by the Hematoxylin & eosin staining and immunoblotting assay.Results: We found that lotus leaf alcohol extract (LAE), not nuciferine, inhibited cell migration significantly in SK-BR-3, MDA-MB-231 and HCC1806 breast cancer cells, and did not change viability of breast cancer cells. The anti-migratory effect of LAE was dependent on TGF-β1 signaling, while independent of Wnt signaling and autophagy influx. Intracellular H2O2 participated in the TGF-β1-related inhibition of cell migration. LAE inhibited significantly the breast cancer cells metastasis in mice models. RNA-sequence analysis showed that extracellular matrix signaling pathways are associated with LAE-suppressed cell migration.Conclusions: Our findings demonstrated that lotus leaf alcohol extract inhibits the cell migration and metastasis of ER- breast cancer via TGF-β1/Erk1/2 and TGF-β1/SMAD3 signaling, which provides a potential therapeutic strategy for ER- breast cancer.

Chemoresistance-Associated Silencing of miR-4454 Promotes Colorectal Cancer Aggression through the GNL3L and NF-κB Pathway

Guanine nucleotide-binding protein-like-3-like (GNL3L) is a crucial regulator of NF-κB signaling that is aberrantly activated during diverse chemoresistance-associated cellular processes. However, the molecular mechanisms of GNL3L tumor initiation and resistant state are largely unknown. Moreover, the identification of predictive biomarkers is necessary to effectively generate therapeutic strategies for metastatic human colorectal cancer (CRC). This study aims to identify how cells acquire resistance to anticancer drugs and whether the downregulation of miR-4454 is associated with the progression of CRC. Here, we have shown that the overexpression of miR-4454 in resistant tumors is a crucial precursor for the posttranscriptional repression of GNL3L in human chemoresistant CRC progression, and we used doxycycline induced miR-4454 overexpression that significantly reduced tumor volume in a subcutaneous injection nude mice model. Together, these observations highlight that the downregulation of miR-4454 in resistant clones is prominently responsible for maintaining their resistance against anticancer drug therapy. Our study indicates that the development of miR-4454 as a microRNA-based therapeutic approach to silence GNL3L may remarkably reduce oncogenic cell survival that depends on GNL3L/NF-κB signaling, making miR-4454 a candidate for treating metastatic human CRC.

The antihistamine deptropine induces hepatoma cell death through blocking autophagosome-lysosome fusion

Background: Autophagy is generally defined as a lysosome-dependent mechanism that degrades cytosolic proteins and organelles at the basal level. Recent studies focused on developing autophagy inhibitors for cancer treatment. Some antihistamines exhibited significant antitumor activity alone or in combination with other therapies in in vitro and clinical studies. However, the underlying mechanisms of how antihistamines inhibit hepatocellular carcinoma proliferation are still unknown. Methods: Two human hepatoma cells were used to examine the effects of 12 benzocycloheptene structural-analogue drugs on the cytotoxicity and underlying molecular mechanisms. The induction of autophagy marker proteins were analyzed by western blot, and the formation of autophagosomes and the fusion between autophagosomes and lysosomes were investigated by immunofluorescence staining. The in vivo anti-cancer activity of drug was evaluated by xenograft nude mice model.Results: We first screened the antiproliferation activity of 12 benzocycloheptene structural-analogue drugs, and results showed that deptropine was the most potent inhibitor of both Hep3B and HepG2 human hepatoma cells. Deptropine significantly increased light chain 3B-II (LC3B-II) expression, but did not induce sequestosome 1 (SQSTM1/p62) degradation in either cell line. Interestingly, other autophagy-related proteins, such as autophagy-related 7 (ATG7), vacuolar protein sorting 34 (VPS34), phosphorylated adenosine 5'-monophosphate-activated protein kinase (AMPK), and phosphorylated Akt, exhibited no significant change in either deptropine-treated cell line. Deptropine also inhibited the processing of cathepsin L from its precursor form to its mature form. Immunofluorescence microscopy showed an increase of autophagosomes in deptropine-treated cells, but deptropine interfered with the fusion between autophagosomes and lysosomes. In a xenograft nude mice model, 2.5 mg/kg deptropine showed a great inhibitory effect on Hep3B tumor growth. Conclusion: These results suggest that deptropine can induce hepatoma cell death in vitro and in vivo, and the underlying mechanisms might be mediated through inhibiting autophagy by blocking autophagosome-lysosome fusion.