Fluoxetine inactivates STAT3/NF-κB signaling and promotes sensitivity to cisplatin in bladder cancer.

Bladder cancer is known as one of the top ten most common cancer types worldwide and can be majorly divided into muscles invasive bladder cancer (MIBC) and non-muscles invasive type (NMIBC). However, the prognosis of BC remains poor under standard treatment including radical cystectomy or concurrent chemoradiotherapy. Numerous studies have reported that the prognosis of BC is associated with the activation of signal transducer and activator of transcription (STAT3) and nuclear factor kappa-B (NF-κB). Fluoxetine, a well-known anti-depressant, has been reported to against various type of cancers. However, it is unclear whether fluoxetine has the capacity to inhibit BC progression by targeting STAT3 and NF-κB-mediated signaling. Here, we used cell viability, apoptosis assay, wound healing assay, invasion/migration assay, Western blotting assay, immunofluorescence staining, as well as animal experiments, to elucidate the efficacy of fluoxetine on in vitro and in vivo BC models. We found that fluoxetine may induce cytotoxicity and intrinsic/extrinsic apoptosis in BC and enhance the potential of cisplatin. Fluoxetine promoted both caspase-dependent and caspase-independent apoptosis signaling by activating caspase-3, 8, 9, apoptosis-inducing factor (AIF), and EndG. Furthermore, fluoxetine suppressed invasion and migration ability and the expression of metastasis-associated genes. Fluoxetine was also found to inactivate the phosphorylation of STAT3 (Tyr705) and NF-κB (Ser536) and suppress the nuclear translocation of NF-κB. In MB49-bearing mice, fluoxetine effectively delayed the progression of BC without inducing general toxicity. In summary, the induction of apoptosis and the inhibition of invasion triggered by fluoxetine are associated with the inactivation of STAT3 and NF-κB.

Plant extracellular vesicles: A novel bioactive nanoparticle for tumor therapy.

Extracellular vesicles are tiny lipid bilayer-enclosed membrane particles, including apoptotic bodies, micro vesicles, and exosomes. Organisms of all life forms can secrete extracellular vesicles into their surrounding environment, which serve as important communication tools between cells and between cells and the environment, and participate in a variety of physiological processes. According to new evidence, plant extracellular vesicles play an important role in the regulation of transboundary molecules with interacting organisms. In addition to carrying signaling molecules (nucleic acids, proteins, metabolic wastes, etc.) to mediate cellular communication, plant cells External vesicles themselves can also function as functional molecules in the cellular microenvironment across cell boundaries. This review introduces the source and extraction of plant extracellular vesicles, and attempts to clarify its anti-tumor mechanism by summarizing the current research on plant extracellular vesicles for disease treatment. We speculate that the continued development of plant extracellular vesicle-based therapeutic and drug delivery platforms will benefit their clinical applications.

STAT3 Inactivation and Induction of Apoptosis Associate With Fluoxetine-inhibited Epithelial-mesenchymal Transition and Growth of Triple-negative Breast Cancer In Vivo.

BACKGROUND/AIM: Breast cancer (BC) is the most common cancer and second leading cause of death in women worldwide. Triple-negative breast cancer (TNBC) is the most aggressive type of BC, while the treatment option is limited and has long been considered as a major unmet need. Meta-analysis indicated the anti-tumor potential of anti-depressants, especially selective serotonin-reuptake inhibitors (SSRIs). The SSRI fluoxetine has been shown to suppress BC and ovarian cancer cell growth; however, whether it suppresses tumor progression in vivo is unclear. MATERIALS AND METHODS: We established an 4T1 bearing animal model, an orthotopic TNBC model, to identify the mechanism and therapeutic efficacy of fluoxetine. RESULTS: Tumor growth evaluated by caliper and computed tomography scan demonstrated the inhibition effect by fluoxetine treatment. Immunohistochemistry showed that the expression of STAT3-mediated epithelial-to-mesenchymal transition (EMT) proteins and apoptosis-related proteins was decreased. CONCLUSION: Fluoxetine may induce an anti-TNBC effect via inactivating STAT3 signaling transduction and triggering the caspase-mediated apoptotic pathway.

Regorafenib enhances antitumor immune efficacy of anti-PD-L1 immunotherapy on oral squamous cell carcinoma.

Oral squamous cells carcinoma (OSCC) is the most common oral malignancy that majorly originated from oral cavity. Though the prognostic and predictive value of targeting checkpoint molecules has been reported on OSCC, the treatment efficacy of monotherapy is remaining limited. Several studies suggested that multikinase inhibitors may show potential to facilitate anti-PD-L1-induced anti-tumor immunity. Regorafenib, an oral multikinase inhibitor has been approved by FDA for various types of cancer treatment. Here, we aim to identify whether regorafenib may boost anti-tumor immunity of anti-PD-L1 in MOC1-bearing OSCC animal model. The alteration of immune cells such as M1/M2-like macrophages (MΦ), cytotoxicity T cells, regulatory T cells (Tregs), and myeloid-derived suppressor cells (MDSCs) after combination of anti-PD-L1 and regorafenib was validated by flow cytometry and immunohistochemistry staining. The combination index analysis (CI=0.89) supported that regorafenib effectively induce anti-OSCC efficacy of anti-PD-L1. Combination of anti-PD-L1 and regorafenib may not only trigger the polarization of M1-like MΦ (CD11b+CD86+) in mice bone marrow (BM) and spleen (SP), but also induce the accumulation and function of CD8+ T cells in tumor-draining lymph node (TDLN) and tumor. In addition, immunosuppressive related cells (MDSCs and Treg) and factors were all decreased by combination therapy in BM, SP and tumor. In sum, regorafenib may improve anti-OSCC efficacy of anti-PD-L1 through systemically and locally upregulating the immunostimulation immunity and suppressing immunosuppression immunity.

Anticancer Efficacy and Mechanism of Amentoflavone for Sensitizing Oral Squamous Cell Carcinoma to Cisplatin.

BACKGROUND/AIM: Nuclear factor kappa B (NF-κB) inactivation and apoptosis activation have been shown to enhance the anticancer effect of cisplatin in oral squamous cell carcinoma (OSCC). Amentoflavone may suppress NF-κB activity and trigger apoptosis in different types of cancer. The aim of this study was to investigate the anticancer effect and mechanism of amentoflavone in combination with cisplatin in OSCC. MATERIALS AND METHODS: We investigated the combination effect and mechanism of amentoflavone and cisplatin via cell viability analysis, flow cytometry-based apoptosis analyses, transwell migration/invasion assay, immunofluorescence staining and western blotting assay. RESULTS: Both amentoflavone and QNZ (NF-κB inhibitor) significantly increased cisplatin-induced cytotoxicity. Amentoflavone reduced cisplatin-triggered NF-κB activity and enhanced cisplatin-induced intrinsic caspase-dependent and independent apoptotic pathways. Moreover, amentoflavone augments cisplatin-suppressed invasion and migration ability of OSCC cells. CONCLUSION: Inactivation of NF-κB and induction of apoptosis through intrinsic caspase-dependent and independent apoptotic pathways are associated with amentoflavone enhanced anti-OSCC efficacy of cisplatin.

ERK/AKT Inactivation and Apoptosis Induction Associate With Quetiapine-inhibited Cell Survival and Invasion in Hepatocellular Carcinoma Cells.

BACKGROUND/AIM: Quetiapine, an atypical antipsychotic, has been encountered as a potential protective agent to suppress various types of tumor growth. However, the inhibitory mechanism of quetiapine in hepatocellular carcinoma (HCC) still remains unclear. The purpose of present study was to investigate the inhibitory mechanism of quetiapine on cell survival and invasion in HCC. MATERIALS AND METHODS: Changes of apoptotic signaling, migration/invasion ability, and signaling transduction involved in cell survival and invasion were evaluated with flow cytometry, migration/invasion, and western blot assays. RESULTS: Quetiapine inhibited cell proliferation and migration/invasion in SK-Hep1 and Hep3B cells. Quetiapine induced extrinsic and intrinsic apoptotic pathways. Activation of extracellular signal-regulated kinases (ERK), protein kinase B (AKT), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), expression of anti-apoptotic, and metastasis-associated proteins were decreased by quetiapine. CONCLUSION: The apoptosis induction, the decreased expression of ERK/AKT-mediated anti-apoptotic and the metastasis-associated proteins were associated with quetiapine-inhibited cell survival and invasion in HCC in vitro.

Hyperforin Induces Apoptosis Through Extrinsic/Intrinsic Pathways and Inhibits NF-ĸB-modulated Survival and Invasion Potential in Bladder Cancer.

BACKGROUND/AIM: Muscle-invasive bladder cancer (MIBC) has long been recognized as a difficult to treat cancer type, thus a new treatment strategy is needed. The major purpose of the present study was to verify the anticancer effect of hyperforin and the mechanism through which it affects tumor cell growth and invasion in bladder cancer in vitro. MATERIALS AND METHODS: Bladder cancer TSGH-8301 cells were treated with different concentrations of hyperforin for different durations of time. The changes in cell viability, production of calcium and reactive oxygen species (ROS), and anti-apoptotic signaling were evaluated using MTT assay, flow cytometry, and western blot analysis. The effect of hyperforin on the expression of nuclear factor-kappaB (NF-ĸB) p65 (Ser276), tumor progression-associated proteins, as well as on cell invasion was investigated using western blotting and cell invasion assay, respectively. RESULTS: Hyperforin significantly induces apoptosis, extrinsic/intrinsic apoptotic signaling, accumulation of cytosol ROS, and calcium signalling. Hyperforin also significantly diminishes the expression of NF-ĸB p65 (Ser276), anti-apoptotic and tumor progression-associated proteins, as well as the cell invasion ability of TSGH-8301 cells. CONCLUSION: Our findings demonstrate that hyperforin triggers apoptosis depending on extrinsic/intrinsic pathways and suppresses NF-ĸB-mediated cell survival as well as the invasive properties of bladder cancer in vitro.