Effective PI3K modulators for improved therapy against malignant tumors and for neuroprotection of brain damage after tumor therapy (Review)

Ameliorative properties of quercetin in the treatment of traumatic brain injury: a mechanistic review based on underlying mechanisms

Traumatic brain injury (TBI) is a leading cause of disability worldwide, with an estimated annual incidence of 27-69 million. TBI is a severe condition that can lead to high mortality rates and long-term cognitive, behavioral, and physical impairments in young adults. It is a significant public health concern due to the lack of effective treatments available. Quercetin, a natural flavonoid found in various fruits and vegetables, has demonstrated therapeutic potential with anti-inflammatory, antioxidant, and neuroprotective properties. Recently, some evidence has accentuated the ameliorating effects of quercetin on TBI. This review discusses quercetin's ability to reduce TBI-related damage by regulating many cellular and molecular pathways. Quercetin in vitro and in vivo studies exhibit promise in reducing inflammation, oxidative stress, apoptosis, and enhancing cognitive function post-TBI. Further clinical investigation into quercetin's therapeutic potential as a readily available adjuvant in the treatment of TBI is warranted in light of these findings. This review adds to our knowledge of quercetin's potential in treating TBI by clarifying its mechanisms of action.

A small-molecule PI3Kα activator for cardioprotection and neuroregeneration

Harnessing the potential beneficial effects of kinase signalling through the generation of direct kinase activators remains an underexplored area of drug development1-5. This also applies to the PI3K signalling pathway, which has been extensively targeted by inhibitors for conditions with PI3K overactivation, such as cancer and immune dysregulation. Here we report the discovery of UCL-TRO-1938 (referred to as 1938 hereon), a small-molecule activator of the PI3Kα isoform, a crucial effector of growth factor signalling. 1938 allosterically activates PI3Kα through a distinct mechanism by enhancing multiple steps of the PI3Kα catalytic cycle and causes both local and global conformational changes in the PI3Kα structure. This compound is selective for PI3Kα over other PI3K isoforms and multiple protein and lipid kinases. It transiently activates PI3K signalling in all rodent and human cells tested, resulting in cellular responses such as proliferation and neurite outgrowth. In rodent models, acute treatment with 1938 provides cardioprotection from ischaemia-reperfusion injury and, after local administration, enhances nerve regeneration following nerve crush. This study identifies a chemical tool to directly probe the PI3Kα signalling pathway and a new approach to modulate PI3K activity, widening the therapeutic potential of targeting these enzymes through short-term activation for tissue protection and regeneration. Our findings illustrate the potential of activating kinases for therapeutic benefit, a currently largely untapped area of drug development.

Fatty Acid Metabolites and the Tumor Microenvironment as Potent Regulators of Cancer Stem Cell Signaling

Individual cancer cells are not equal but are organized into a cellular hierarchy in which only a rare few leukemia cells can self-renew in a manner reminiscent of the characteristic stem cell properties. The PI3K/AKT pathway functions in a variety of cancers and plays a critical role in the survival and proliferation of healthy cells under physiologic conditions. In addition, cancer stem cells might exhibit a variety of metabolic reprogramming phenotypes that cannot be completely attributed to the intrinsic heterogeneity of cancer. Given the heterogeneity of cancer stem cells, new strategies with single-cell resolution will become a powerful tool to eradicate the aggressive cell population harboring cancer stem cell phenotypes. Here, this article will provide an overview of the most important signaling pathways of cancer stem cells regarding their relevance to the tumor microenvironment and fatty acid metabolism, suggesting valuable strategies among cancer immunotherapies to inhibit the recurrence of tumors.

Pleiotropic Signaling by Reactive Oxygen Species Concerted with Dietary Phytochemicals and Microbial-Derived Metabolites as Potent Therapeutic Regulators of the Tumor Microenvironment

The excessive generation of reactive oxygen species (ROS) plays a pivotal role in the pathogenesis of diseases. ROS are central to cellular redox regulation and act as second messengers to activate redox-sensitive signals. Recent studies have revealed that certain sources of ROS can be beneficial or harmful to human health. Considering the essential and pleiotropic roles of ROS in basic physiological functions, future therapeutics should be designed to modulate the redox state. Dietary phytochemicals, microbiota, and metabolites derived from them can be expected to be developed as drugs to prevent or treat disorders in the tumor microenvironment.

miRNA-425-5p enhances diffuse large B cell lymphoma growth by targeting PTEN

BACKGROUND

At present, cancer is one of the greatest threats to mankind, and is associated with the highest rates of morbidity and comorbidity. Recently, the advancements in molecular biology have led to an in-depth understanding of the underlying pathophysiology, which may further impact the lead time in the context of early discovery and effective therapy of cancer. Therefore, the present study proposes a better understanding of the role of micro(miR)-425-5p in diffuse large B-cell lymphoma (DLBC).

METHODS

qRT-PCR was carried out to detect the relevant proteins, miRNA and mRNA RNA gene expression in DLBC cells. The effect of miR-425-5p on DLBC growth was examined by CCK-8 and colony formation assays. The binding relationship between genes was verified by dual-luciferase reporter gene assay.

RESULTS

We demonstrated how the over-expression of miR-425-5p can lead to increased progression of DLBC by increasing the cellular proliferation rate and colony-forming ability. Additionally, we also found that the expression of miR-425-5p could be significantly inhibited on the basis of phosphatase and tensin homolog (PTEN) signaling pathways.

CONCLUSIONS

The present study concludes that miR-425-5p is responsible for the oncogenic progression and relapse of DLBC tumorigenesis via PTEN/PI3K signaling, which can thus be effectively used to achieve better therapeutic outcomes.

The Biological Function of TUSC7/miR-1224-3p Axis in Triple-Negative Breast Cancer

Background

Triple-negative breast cancers (TNBC), comprising about 20% of breast cancers, have a poor prognosis. Currently, there is no effective target therapy for TNBC. LncRNA TUSC7 has been identified as a tumor suppressor in osteosarcoma and colorectal cancer. In this study, we investigated the clinical significance and the biological function of TUSC7 in breast cancer.

Methods

We retrospectively evaluated the expression level and clinical significance of TUSC7 in 90 paired breast cancer tissues and normal tissues. The proliferation, migration, and invasion assays were performed to investigate the biological function of TUSC7 in breast cancer. Finally, microarray, a luciferase reporter assay, and quantitative real-time polymerase chain reaction (qPCR) were used to explore the potential underlying mechanism of tumor suppressor role of TUSC7.

Results

Low TUSC7 expression was found to be an independent prognostic factor of poor overall survival (OS) in TNBC patients. Ectopic expression of TUSC7 inhibited tumor cell growth both in vitro and in vivo. TUSC7 overexpression significantly promoted the sensitivity of MDA-MB-468 cells to paclitaxel and carboplatin. In terms of the mechanism, TUSC7 might perform its biological function through binding with miR-1224-3P and regulating its expression level. Besides, genes in cell cycle pathways, such as BUB3 (budding uninhibited by benzimidazoles 3) and TGF-ß (targeting transforming growth factor β) pathways were downregulated, and genes involved in the MAPK (mitogen-activated protein kinase) (TGFBR2, transforming growth factor-beta receptor 2), PI3K-AKT (phosphoinositide 3-kinase- AKT serine/threonine kinase 1) and NF-κB (nuclear factor-kappa B subunit) pathways were upregulated in TUSC7 knockdown MDA-MB-231 cells.

Conclusion

The low TUSC7 expression is an independent prognostic factor of poor OS of TNBC patients. TUSC7 might inhibit breast cancer cell growth and metastasis both in vitro and vivo through binding with miR-1224-3P and regulating MAPK, PI3K/AKT, and NF-κB signaling pathways.

Peroxisome Proliferator-Activated Receptor γ Coactivator 1α Activates Vascular Endothelial Growth Factor That Protects Against Neuronal Cell Death Following Status Epilepticus through PI3K/AKT and MEK/ERK Signaling

Status epilepticus may cause molecular and cellular events, leading to hippocampal neuronal cell death. Peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) is an important regulator of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2), also known as fetal liver kinase receptor 1 (Flk-1). Resveratrol is an activator of PGC-1α. It has been suggested to provide neuroprotective effects in epilepsy, stroke, and neurodegenerative diseases. In the present study, we used microinjection of kainic acid into the left hippocampal CA3 region in Sprague Dawley rats to induce bilateral prolonged seizure activity. Upregulating the PGC-1α pathway will increase VEGF/VEGFR2 (Flk-1) signaling and further activate some survival signaling that includes the mitogen activated protein kinase kinase (MEK)/mitogen activated protein kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways and offer neuroprotection as a consequence of apoptosis in the hippocampal neurons following status epilepticus. Otherwise, downregulation of PGC-1α by siRNA against pgc-1α will inhibit VEGF/VEGFR2 (Flk-1) signaling and suppress pro-survival PI3K/AKT and MEK/ERK pathways that are also accompanied by hippocampal CA3 neuronal cell apoptosis. These results may indicate that the PGC-1α induced VEGF/VEGFR2 pathway may trigger the neuronal survival signaling, and the PI3K/AKT and MEK/ERK signaling pathways. Thus, the axis of PGC-1α/VEGF/VEGFR2 (Flk-1) and the triggering of downstream PI3K/AKT and MEK/ERK signaling could be considered an endogenous neuroprotective effect against apoptosis in the hippocampus following status epilepticus.

Coix lacryma-jobi var. ma-yuen Stapf sprout extract induces cell cycle arrest and apoptosis in human cervical carcinoma cells

Background

Cervical cancer is the second-leading cause of cancer-related mortality in females. Coix lacryma-jobi L. var. ma-yuen (Rom.Caill.) Stapf ex Hook. f. is the most widely recognized medicinal herb for its remedial effects against inflammation, endocrine system dysfunctions, warts, chapped skin, rheumatism, and neuralgia and is also a nourishing food.

Methods

To investigate the activity of Coix lacryma-jobi sprout extract (CLSE) on cell proliferation in human cervical cancer HeLa cells, we conducted a Cell Counting Kit-8 (CCK-8) assay. Flow-cytometric analysis and western blot analysis were performed to verify the effect of CLSE on the regulation of the cell cycle and apoptosis in HeLa cells.

Results

We observed that CLSE significantly inhibited cell proliferation. Furthermore, CLSE dose-dependently promoted cell cycle arrest at the sub-G1/ S phase in HeLa cells, as detected by bromodeoxyuridine (BrdU) staining. The cell-cycle-arrest effects of CLSE in HeLa cells were associated with downregulation of cyclin D1 and cyclin-dependent kinases (CDKs) 2, 4, and 6. Moreover, CLSE induced apoptosis, as determined by flow-cytometric analysis and nuclear DNA fragmentation with Annexin V/propidium iodide (PI) and 4′6′-diamidino-2-phenylindole (DAPI) staining. Induction of apoptosis by CLSE was involved in inhibition of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) and upregulation of the apoptotic proteins p53, cleaved poly (ADP-ribose) polymerase (PARP), cleaved caspase-3, and cleaved caspase-8. Finally, we observed that CLSE inactivated the phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) pathways.

Conclusions

CLSE causes cell cycle arrest and apoptotic cell death through inactivation of the PI3K/AKT pathway in HeLa cells, suggesting it is a viable therapeutic agent for cervical cancer owing to its anticancer effects.

Lactate and pyruvate promote oxidative stress resistance through hormetic ROS signaling

L-lactate was long considered a glycolytic by-product but is now being recognized as a signaling molecule involved in cell survival. In this manuscript, we report the role of L-lactate in stress resistance and cell survival mechanisms using neuroblastoma cells (SH-SY5Y) as well as the C. elegans model. We observed that L-lactate promotes cellular defense mechanisms, including Unfolded Protein Response (UPR) and activation of nuclear factor erythroid 2-related factor 2 (NRF2), by promoting a mild Reactive Oxygen Species (ROS) burst. This increase in ROS triggers antioxidant defenses and pro-survival pathways, such as PI3K/AKT and Endoplasmic Reticulum (ER) chaperones. These results contribute to the understanding of the molecular mechanisms involved in beneficial effects of L-lactate, involving mild ROS burst, leading to activation of unfolded protein responses and detoxification mechanisms. We present evidence that this hormetic mechanism induced by L-lactate protects against oxidative stress in vitro and in vivo. This work contributes to the identification of molecular mechanisms, which could serve as targets for future therapeutic approaches for cell protection and aging-related disorders.

Antidepressive effects of kaempferol mediated by reduction of oxidative stress, proinflammatory cytokines and up-regulation of AKT/β-catenin cascade

Kaempferol (KFL), the major constituent of various fruits and vegetables, could attenuate oxidaitve stress and inflammation. The aims of the present study were to explore the ameliorative abilities of KFL on the depressive-like behaviors in a chronic social defeat stress (CSDS) mouse model, and to determine the potential mechanisms on oxidative stress, neuroinflammation, and AKT/β-catenin signaling pathway. Three behavioral tests, sucrose preference test (SPT), social interaction test (SIT), and tail suspension test (TST), were used to evaluate the antidepressive effects of KFL in CSDS mice. Activity levels of antioxidant enzyme, superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione s-transferase (GST), and concentrations of malonaldehyde (MDA) and protein carbonylation in the prefrontal cortex were assessed by commercial kits, respectively. Elisa was used to detect the levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α). Q-PCR was used to determine the mRNA level of CD-11b. Furthermore, activity level of AKT/β-catenin signaling in the prefrontal cortex of CSDS mice was investigated by western blot. In addition, LY294002, a PI3-K inhibitor, was used to investigate the role of AKT/β-catenin signaling in the antidepressant effects of KFL. Social defeat stress reduced the bodyweights, sucrose consumptions, social interaction times, and the tail suspension mobility times in mice. CSDS mice were also exhibited remarkablely increased levels in oxidative stress markers, inflammatory mediators, and decreased activity of AKT/β-catenin cascade in the prefrontal cortex, which were reversed by treatment with KFL. Interestingly, LY294002 appeared to partly inhibit the overall KFL-mediated protective effects in the CSDS mice. These results confirmed that KFL exerted antidepressive effects, which might be mediated, at least in part, by enhanced antioxidant abilities and anti-inflammation effects via up-regulation AKT/β-catenin cascade activity in the prefrontal cortex of CSDS mice. Thus, KFL might be a promising, effective, and safe food medicine for depression treatment.

Anticancer activity of 23,24-dihydrocucurbitacin B against the HeLa human cervical cell line is due to apoptosis and G2/M cell cycle arrest

Cervical cancer is one of the primary causes of cancer-associated mortality worldwide. Due to the increasing incidence of cervical cancer, multiple treatment options are required. Initial responses to chemotherapy and surgical interventions are generally positive, however patients often experience relapse and tumor recurrence. Currently, the effects of cucurbitacins on different types of cancer are being investigated, as they exhibit a wide variety of bioactivities. The anticancer activity of the cucurbitacin 23,24-dihydrocucurbitacin B against a panel of human cervical cancer cell lines was investigated in the current study. Cell viability was determined using an MTT assay and apoptosis was detected using DAPI staining. The proportion of apoptotic cells, cell cycle distribution, mitochondrial membrane potential (ΔΨ_m) and reactive oxygen species (ROS) levels were estimated using flow cytometry. Protein expression was determined using western blot analysis. The results of the current study indicated that 23,24-dihydrocucurbitacin B inhibited the viability of human cervical cancer cell lines and had an IC₅₀ of 40-60 µM. However, its cytotoxic effects were much less pronounced in normal epithelial fr2 and HerEpiC cells, where it had an IC₅₀ of 125 µM. The underlying mechanisms of this were further studied and the results demonstrated that 23,24-dihydrocucurbitacin B induced apoptosis in HeLa cells and caused ROS-mediated shifts in the ΔΨ_m. Additionally, it caused the cell cycle arrest of HeLa cells at the G₂/M checkpoint. The phosphoinositide 3 kinase/protein kinase B/mechanistic target of rampamycin (PI3K/AKT/mTOR) cascade may serve an important role in cancer tumorigenesis, progression and resistance to chemotherapy. The results indicated that 23,24-dihydrocucurbitacin B significantly decreased the expression of important proteins in the PI3K/Akt/mTOR cascade. Taken together, these results suggest that 23,24-dihydrocucurbitacin B may be novel method of treating cervical cancer.

Phytochemical allylguaiacol exerts a neuroprotective effect on hippocampal cells and ameliorates scopolamine-induced memory impairment in mice

Allylguaiacol is a phytochemical occurring in various plants such as cloves, cinnamon, basil, and nutmeg. Pharmacological effects of allylguaiacol include antimicrobial, anti-inflammatory, anticancer, antioxidant, and neuroprotective activity. Although allylguaiacol is considered to have neuroprotective effects, there is no report on its regulatory mechanisms at the molecular level. In the present study, we investigated the mechanisms of allylguaiacol as an antioxidant and neuroprotective agent using hydrogen peroxide (H₂O₂)-treated HT22 hippocampal cells. Allylguaiacol increased the scavenging activities of free radicals 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), and enhanced the expression of antioxidant enzymes manganese superoxide dismutase (MnSOD) and catalase. In addition, allylguaiacol inhibited H₂O₂-induced damage of HT22 with increasing production of brain-derived neurotrophic factor (BDNF), phosphorylation of phosphoinositide 3-kinase (PI3K), and cyclic AMP response element-binding protein (CREB). Furthermore, antibody microarray data revealed that phospho-regulation of nuclear factor kappa B (NF-κB) p65 and death domain-associated protein (DAXX) is involved in protection against neuronal cell damage. In a mouse model of short-term memory impairment, allylguaiacol (2.5 or 5mg/kg) significantly ameliorated scopolamine-mediated cognitive impairment in a passive avoidance task. In addition, allylguaiacol significantly increased the expression of TrkA and B in the hippocampus from scopolamine-treated mice. Taken together, our findings suggest that allylguaiacol exerts a neuroprotective effect through the antioxidant activation and protein regulation of NF-κB p65 and DAXX-related signaling. The ameliorating effect of allylguaiacol may be useful for treatment of memory impairment in Alzheimer's and its related diseases.