Improvement of Docetaxel Efficacy through Simultaneous Blockade of Transcription Factors NF-κB and STAT-3 Using Pentoxifylline and Stattic in Prostate Cancer Cells.

Prostate cancer (PCa) is a common and deadly disease in men. It is often diagnosed at advanced stages, at which point patients are treated mainly with docetaxel (DTX), which is effective but limited by resistance and side effects. Overactivation of the transcription factors NF-κB and STAT-3 plays a critical role in the development, progression, and chemoresistance of PCa. In this regard, the blockade of NF-κB with pentoxifylline (PTX) or STAT-3 with Stattic (STT) is known to increase the sensitivity of tumor cells to chemotherapy in both in vitro and in vivo models. We investigated whether simultaneous blockade with PTX and STT increases the efficacy of the DTX treatment in inducing apoptosis in metastatic castration-resistant PCa DU-145 cells. Our results showed that the combination of PTX + STT led to higher levels of apoptosis, regardless of whether or not DTX was present in the treatment. Determining caspases and ΔΨm indicates that the intrinsic caspase pathway of apoptosis is principally favored. In addition, this combination inhibited proliferation and colony formation and arrested the cell cycle in the G1 phase. These results indicate that the combination of the PTX + STAT-3 inhibitor could potentiate DTX effectively, opening the possibility of effective treatments in PCa.

Effects of Arborvitae (Thuja plicata) Essential Oil on Cervical Cancer Cells: Insights into Molecular Mechanisms.

AIMS: This study aimed to assess the effects of AEO in an in vitro model of cell lines derived from cervical cancer-namely, HeLa and SiHa-by screening for AEO's cytotoxic properties and examining its influence on the modulation of gene expression. BACKGROUND: Cervical cancer stands as a prevalent global health concern, affecting millions of women worldwide. The current treatment modalities encompass surgery, radiation, and chemotherapy, but significant limitations and adverse effects constrain their effectiveness. Therefore, exploring novel treatments that offer enhanced efficacy and reduced side effects is imperative. Arborvitae essential oil, extracted from Thuja Plicata, has garnered attention for its antimicrobial, anti-inflammatory, immunomodulatory, and tissue-remodeling properties; however, its potential in treating cervical cancer remains uncharted. OBJECTIVE: The objective of this study was to delve into the molecular mechanisms induced by arborvitae essential oil in order to learn about its anticancer effects on cervical cancer cell lines. METHODS: The methods used in this study were assessments of cell viability using WST-1 and annexin V- propidium iodide, mRNA sequencing, and subsequent bioinformatics analysis. RESULTS: The findings unveiled a dose-dependent cytotoxic effect of arborvitae essential oil on both HeLa and SiHa cell lines. Minor effects were observed only at very low doses in the HaCaT non-tumorigenic human keratinocyte cells. RNA-Seq bioinformatics analysis revealed the regulatory impact of arborvitae essential oil on genes enriched in the following pathways: proteasome, adherens junctions, nucleocytoplasmic transport, cell cycle, proteoglycans in cancer, protein processing in the endoplasmic reticulum, ribosome, spliceosome, mitophagy, cellular senescence, and viral carcinogenesis, among others, in both cell lines. It is worth noting that the ribosome and spliceosome KEGG pathways are the most significantly enriched pathways in HeLa and SiHa cells. CONCLUSION: Arborvitae essential oil shows potential as a cytotoxic and antiproliferative agent against cervical cancer cells, exerting its cytotoxic properties by regulating many KEGG pathways.

Pentoxifylline Inhibits TNF-α/TGF-ß1-Induced Epithelial-Mesenchymal Transition via Suppressing the NF-κB Pathway and SERPINE1 Expression in CaSki Cells.

Cervical cancer (CC) is one of the most common and deadly types of female cancer worldwide. Late diagnosis in CC increases the risk of tumor cells spreading to distant organs (metastasis). The epithelial-mesenchymal transition (EMT) is a fundamental process of cancer metastasis. Inflammation can lead to tumor progression, EMT induction, and metastasis. The inflammatory microenvironment is a potent inducer of EMT; inflammatory cytokines such as Tumor Necrosis Factor-alpha (TNF-α) and Transforming growth factor-beta (TGF-ß1) activate transcriptional factors such as STAT3, Snail, Smad, and the Nuclear Factor kappa light-chain-enhancer of activated beta cells (NF-κΒ), which drive EMT. Anti-inflammatory compounds may be an option in the disruption of EMT. PenToXifylline (PTX) possesses potent anti-inflammatory effects by inhibiting NF-κB activity. In addition, PTX exerts an anti-fibrotic effect by decreasing Smad2/3/4. We hypothesize that PTX could exert anti-EMT effects. CaSki human cervical tumor cells were exposed to TNF-α 10 ng/mL and TGF-ß1 alone or in combination for 5 days. Our results revealed that TNF-α and TGF-ß1 induced N-cadherin and Vimentin, confirming the induction of EMT. Furthermore, the combination of cytokines synergized the expression of mesenchymal proteins, enhanced IκBα and p65 phosphorylation, and upregulated Serpin family E member 1 (SERPINE1) mRNA. PTX pretreatment prior to the addition of TNF-α and TGF-ß1 significantly reduced N-cadherin and Vimentin levels. To our knowledge, this is the first time that this effect of PTX has been reported. Additionally, PTX reduced the phosphorylation of IκB-α and p65 and significantly decreased SERPINE1 expression, cell proliferation, migration, and invasion. In conclusion, PTX may counteract EMT in cervical cancer cells by decreasing the NF-κB and SERPINE1.

Pentoxifylline Enhances the Apoptotic Effect of Carboplatin in Y79 Retinoblastoma Cells.

BACKGROUND/AIM: Retinoblastoma (RB) is the most common primary intraocular malignancy. Carboplatin (CPt) is a DNA damage-inducing agent that is widely used for the treatment of RB. Unfortunately, this drug also activates the transcription factor nuclear factor-kappa B (NF-ĸB), leading to promotion of tumor survival. Pentoxifylline (PTX) is a drug that inhibits the phosphorylation of I kappa B-alpha (IĸBα) in serines 32 and 36, and this disrupts NF-ĸB activity that promotes tumor survival. The goal of this study was to evaluate the effect of the PTX on the antitumor activity of CPt. MATERIALS AND METHODS: Y79 RB cells were treated with CPt, PTX, or both. Cell viability, apoptosis, loss of mitochondrial membrane potential, the activity of caspase-9, -8, and -3, cytochrome c release, cell-cycle progression, p53, and phosphorylation of IĸBα, and pro- and anti-apoptotic genes were evaluated. RESULTS: Both drugs significantly affected the viability of the Y79 RB cells in a time- and dose-dependent manner. The PTX+CPt combination exhibited the highest rate of apoptosis, a decrease in cell viability and significant caspase activation, as well as loss of mitochondrial membrane potential, release of cytochrome c, and increased p53 protein levels. Cells treated with PTX alone displayed decreased I kappa B-alpha phosphorylation, compared to the CPt treated group. In addition, the PTX+CPt combination treatment induced up-regulation of the proapoptotic genes Bax, Bad, Bak, and caspases- 3, -8, and -9, compared to the CPt and PTX individual treated groups. CONCLUSION: PTX induces apoptosis per se and increases the CPt-induced apoptosis, augmenting its antitumor effectiveness.

Dysregulation of the Th1/Th2 cytokine profile is associated with immunosuppression induced by hypothalamic-pituitary-adrenal axis activation in mice.

Hypothalamic-pituitary-adrenal (HPA) axis activation-induced immunosuppression is associated with increased concentration of circulating corticosterone and impaired cellular immune responses. The purpose of this study was to investigate the effect of chronic HPA axis activation on the cellular immune response, Th1/Th2 cytokine profile, and concentration of corticosterone. Mice were divided into two groups: a control group comprised of healthy, untreated mice that received no stress, and an HPA axis-activated group that received stress through electric shock (ES). The delayed-type hypersensitivity reaction to dinitrofluorobenzene, splenocyte proliferative response to mitogens Concanavalin A and lipopolysaccharide, Th1 and Th2 profile, and TGF-beta1 production were measured in plasma and in culture supernatants. The corticosterone concentration was also measured in plasma. In the ES group, elevated plasma corticosterone concentration was associated with immunosuppression and a significant decrease in plasma concentrations of IL-2, IL-4, and TGF-beta1. In vitro IL-2 production in response to Con A was significantly lower in the ES group than in the control group. TGF-beta1 production in nonstimulated and stimulated cultures in response to either mitogen was significantly lower in the ES group than in the control group. Plasma concentrations of IFN-gamma and IL-10 did not differ significantly between groups. The concentrations of IFN-gamma, IL-4, and IL-10 in the supernatants of splenocytes stimulated with either mitogen and IL-4 production by nonstimulated cells were significantly higher in the ES group than in the control group. These results suggest that corticosterone mediates the immunosuppression induced by HPA axis activation, and induces dysregulation of the Th1/Th2 cytokine profile.

Effect of Ginkgo biloba extract EGb 761 on the nonspecific and humoral immune responses in a hypothalamic-pituitary-adrenal axis activation model.

We evaluated the immune response of healthy control and stressed Wistar rats submitted to hypothalamic-pituitary-adrenal (HPA) axis activation. Rats were treated with Ginkgo biloba extract (EGb 761) orally (100 mg/kg per day for 7 days). EGb 761 stimulated the digestion index of peritoneal and alveolar macrophages (PM and AM) of stressed rats. Likewise, the cellular immune response measured using the delayed-type hypersensitivity response to sheep red blood cells (SRBC) and the humoral immune response (measured through an anti-SRBC response), were also restored in stressed rats. Thus, this G. biloba extract possesses immunostimulatory activity in addition to its broad spectrum of pharmacological effects.

Effect of Ginkgo biloba extract, EGb 761, on the cellular immune response in a hypothalamic-pituitary-adrenal axis activation model in the rat.

We evaluated the effects of Ginkgo biloba extract (EGb 761) on the cellular immune response of rats with immunosuppression induced by activation of the hypothalamic-pituitary-adrenal (HPA) axis. Groups of five rats were subjected to chronic stress by the application of daily electric shocks (ES) over 7 days. This stress produced a significant decrement in the delayed-type hypersensitivity response (DTH) to dinitrofluorobenzene (DNFB), and a decrease in the proliferation index of splenocytes. Treatment with oral doses of the phytopharmaceutical EGb 761 (100 mg/kg per day over 7 days) restored both the DTH response to DNFB and the proliferation index. EGb 761 has stress-alleviating properties through its moderation of corticosterone levels. It also possesses antioxidant activity that may contribute to its effects on the immune response. Our observations indicate that the phytopharmaceutical EGb 761 possesses immunostimulatory properties.