Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway

Metabolomics analyses reveal the crucial role of ERK in regulating metabolic pathways associated with the proliferation of human cutaneous T-cell lymphoma cells treated with Glabridin

Cutaneous T-cell lymphomas (CTC) are a heterogeneous group of T-cell lymphoproliferative malignancies of the skin with limited treatment options, increased resistance and remission. Metabolic reprogramming is vital in orchestrating the uncontrolled growth and proliferation of cancer cells. Importantly, deregulated signalling plays a significant role in metabolic reprogramming. Considering the crucial role of metabolic reprogramming in cancer-cell growth and proliferation, target identification and the development of novel and multi-targeting agents are imperative. The present study explores the underlying mechanisms and metabolic signalling pathways associated with Glabridin mediated anti-cancer actions in CTCL. Our results show that Glabridin significantly inhibits the growth of CTCL cells through induction of programmed cell death (PCD) such as apoptosis, autophagy and necrosis. Interestingly, results further show that Glabridin induces PCD in CTCL cells by targeting MAPK signalling pathways, particularly the activation of ERK. Further, Glabridin also sensitized CTCL cells to the anti-cancer drug, bortezomib. Importantly, LC-MS-based metabolomics analyses further showed that Glabridin targeted multiple metabolites and metabolic pathways intricately involved in cancer cell growth and proliferation in an ERK-dependent fashion. Overall, our findings revealed that Glabridin induces PCD and attenuates the expression of regulatory proteins and metabolites involved in orchestrating the uncontrolled proliferation of CTCL cells through ERK activation. Therefore, Glabridin possesses important features of an ideal anti-cancer agent.

Exposure of Legionella pneumophila to low-shear modeled microgravity: impact on stress response, membrane lipid composition, pathogenicity to macrophages and interrelated genes expression

Here, we studied the effect of low-shear modeled microgravity (LSMMG) on cross stress resistance (heat, acid, and oxidative), fatty acid content, and pathogenicity along with alteration in expression of stress-/virulence-associated genes in Legionella pneumophila. The stress resistance analysis result indicated that bacteria cultivated under LSMMG environments showed higher resistance with elevated D-values at 55 °C and in 1 mM of hydrogen peroxide (H2O2) conditions compared to normal gravity (NG)-grown bacteria. On the other hand, there was no significant difference in tolerance (p < 0.05) toward simulated gastric fluid (pH-2.5) acid conditions. In fatty acid analysis, our result showed that a total amount of saturated and cyclic fatty acids was increased in LSMMG-grown cells; as a consequence, they might possess low membrane fluidity. An upregulated expression level was noticed for stress-related genes (hslV, htrA, grpE, groL, htpG, clpB, clpX, dnaJ, dnaK, rpoH, rpoE, rpoS, kaiB, kaiC, lpp1114, ahpC1, ahpC2, ahpD, grlA, and gst) under LSMMG conditions. The reduced virulence (less intracellular bacteria and less % of induce apoptosis in RAW 264.7 macrophages) of L. pneumophila under LSMMG conditions may be because of downregulation related genes (dotA, dotB, dotC, dotD, dotG, dotH, dotL, dotM, dotN, icmK, icmB, icmS, icmT, icmW, ladC, rtxA, letA, rpoN, fleQ, fleR, and fliA). In the LSMMG group, the expression of inflammation-related factors, such as IL-1α, TNF-α, IL-6, and IL-8, was observed to be reduced in infected macrophages. Also, scanning electron microscopy (SEM) analysis showed less number of LSMMG-cultivated bacteria attached to the host macrophages compared to NG. Thus, our study provides understandings about the changes in lipid composition and different genes expression due to LSMMG conditions, which apparently influence the alterations of L. pneumophila' stress/virulence response.

The global perspective on peroxisome proliferator-activated receptor γ (PPARγ) in ectopic fat deposition: A review

Excessive expansion of adipocytes can have unhealthy consequences as excess free fatty acids enter other tissues and cause ectopic fat deposition by resynthesizing triglycerides. This lipid accumulation in various tissues is harmful and can increase the risk of related metabolic diseases such as type II diabetes, cardiovascular disease, and insulin resistance. Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily that play a key role in energy metabolism as fatty acid metabolism sensors, and peroxisome proliferator-activated receptor γ (PPARγ) is the main subtype responsible for fat cell differentiation and adipogenesis. In this paper, we introduce the main structure and function of PPARγ and its regulatory role in the process of lipogenesis in the liver, kidney, skeletal muscle, and pancreas. This information can serve as a reference for further understanding the regulatory mechanisms and measures of the PPAR family in the process of ectopic fat deposition.

RAIDS atlas of significant genetic and protein biomarkers in cervical cancer

Loss of function in epigenetic acting genes together with driver alterations in the PIK3CA pathway have been shown significantly associated with poor outcome in cervical squamous cell cancer. More recently, a CoxBoost analysis identified 16 gene alterations and 30 high level activated proteins to be of high interest, due to their association with either good or bad outcome, in the context of treatment received by chemoradiation. The objectives here were to review and confirm the significance of these molecular alterations as suggested by literature reports and to pinpoint alternate treatments options for poor-responders to chemoradiation.

Glabridin plays dual action to intensify anti-metastatic potential of paclitaxel via impeding CYP2C8 in liver and CYP2J2/EETs in tumor of an orthotopic mouse model of breast cancer

In spite of unprecedented advances in modern cancer therapy, there is still a dearth of targeted therapy to circumvent triple-negative breast cancer (TNBC). Paclitaxel is the front-line therapy against TNBC, but the main constraints of its treatment are dose-related adverse effects and emerging chemoresistance. In this context, glabridin (phytoconstituent from Glycyrrhiza glabra) is reported to hit multiple signalling pathways at the in-vitro level, but hardly any information is known at the in-vivo level. We aimed here to elucidate glabridin potential with an underlying mechanism in combination with a low dose of paclitaxel using a highly aggressive mouse mammary carcinoma model. Glabridin potentiated the anti-metastatic efficacy of paclitaxel by substantially curtailing tumor burden and diminishing lung nodule formation. Moreover, glabridin remarkably attenuated epithelial-mesenchymal transition (EMT) traits of hostile cancer cells via up-regulating (E-cadherin & occludin) and down-regulating (Vimentin & Zeb1) vital EMT markers. Besides, glabridin amplified apoptotic induction effect of paclitaxel in tumor tissue by declining or elevating pro-apoptotic (Procaspase-9 or Cleaved Caspase-9 & Bax) and reducing anti-apoptotic (Bcl-2) markers. Additionally, concomitant treatment of glabridin and paclitaxel predominantly lessened CYP2J2 expression with marked lowering of epoxyeicosatrienoic acid (EET)'s levels in tumor tissue to reinforce the anti-tumor impact. Simultaneous administration of glabridin with paclitaxel notably enhanced plasma exposure and delayed clearance of paclitaxel, which was mainly arbitrated by CYP2C8-mediated slowdown of paclitaxel metabolism in the liver. The fact of intense CYP2C8 inhibitory action of glabridin was also ascertained using human liver microsomes. Concisely, glabridin plays a dual role in boosting anti-metastatic activity by augmenting paclitaxel exposure via CYP2C8 inhibition-mediated delaying paclitaxel metabolism and limiting tumorigenesis via CYP2J2 inhibition-mediated restricting EETs level. Considering the safety, reported protective efficacy, and the current study results of boosted anti-metastatic effects, further investigations are warranted as a promising neoadjuvant therapy for crux paclitaxel chemoresistance and cancer recurrence.

Unveiling the therapeutic potential of natural-based anticancer compounds inducing non-canonical cell death mechanisms

In the Mid-19th century, Rudolf Virchow considered necrosis to be a prominent form of cell death; since then, pathologists have recognized necrosis as both a cause and a consequence of disease. About a century later, the mechanism of apoptosis, another form of cell death, was discovered, and we now know that this process is regulated by several molecular mechanisms that "programme" the cell to die. However, discoveries on cell death mechanisms are not limited to these, and recent studies have allowed the identification of novel cell death pathways that can be molecularly distinguished from necrotic and apoptotic cell death mechanisms. Moreover, the main goal of current cancer therapy is to discover and develop drugs that target apoptosis. However, resistance to chemotherapeutic agents targeting apoptosis is mainly responsible for the failure of clinical therapy and adverse side effects of the chemotherapeutic agents currently in use pose a major threat to the well-being and lives of patients. Therefore, the development of natural-based anticancer drugs with low cellular and organismal side effects is of great interest. In this comprehensive review, we thoroughly examine and discuss natural anticancer compounds that specifically target non-canonical cell death mechanisms.

Glabridin inhibits urothelial bladder carcinoma cell growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest

Glabridin (GLA) has a variety of biological activities and therapeutic effects in cancers. Whereas the effect of GLA on urothelial bladder carcinoma (UBC) cells and its underlying mechanisms remain unknown. The study revealed the effect of GLA on UBC and the potential mechanism of inducing cell apoptosis in vivo and in vitro. After treated with different concentrations of GLA, the cell activity decreased in a time- and dose-dependent manner. The IC₅₀ values of BIU-87 and EJ cells at 48 h were 6.02 μg/ml (18.6 μm) and 4.36 μg/ml (13.4 μm), respectively. Additionally, GLA-induced apoptosis and cycle arrest of BIU-87 and EJ cells in G2 phase. Furthermore, wound healing experiments showed that GLA significantly reduced the migration activities of BIU-87 and EJ cells. Mechanically, GLA obviously increased the expression of BIM, BAK1, and CYCS in both mRNA and protein levels, which led to the activation of the endogenous apoptotic pathway. Finally, GLA remarkably inhibited the growth of UBC tumors in vivo. In summary, GLA inhibited UBC cells growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest, highlighting that GLA could be utilized as a component to design a novel anti-UBC drug.

Review on the Diverse Biological Effects of Glabridin

Glabridin is a prenylated isoflavan from the roots of Glycyrrhiza glabra Linne and has posed great impact on the areas of drug development and medicine, due to various biological properties such as anti-inflammation, anti-oxidation, anti-tumor, anti-microorganism, bone protection, cardiovascular protection, neuroprotection, hepatoprotection, anti-obesity, and anti-diabetes. Many signaling pathways, including NF-κB, MAPK, Wnt/β-catenin, ERα/SRC-1, PI3K/AKT, and AMPK, have been implicated in the regulatory activities of glabridin. Interestingly, glabridin has been considered as an inhibitor of tyrosinase, P-glycoprotein (P-gp), and CYP2E1 and an activator of peroxisome proliferator-activated receptor γ (PPARγ), although their molecular regulating mechanisms still need further investigation. However, poor water solubility and low bioavailability have greatly limited the clinical applications of glabridin. Hopefully, several effective strategies, such as nanoemulsions, microneedles, and smartPearls formulation, have been developed for improvement.

The toxicity mechanism of glabridin in prostate cancer cells is involved in reactive oxygen species-dependent PI3K/Akt pathway: Integrated utilization of bioinformatic analysis and in vitro test validation

Glabridin is a prenylated isoflavonoid with considerable anticancer property. Reactive oxygen species (ROS) have evolved as regulators of many cellular signaling pathways in prostate cancer (PC). However, the role of ROS signaling in the anticancer activity of glabridin has not been investigated. Here, we attempted to evaluate the effect of glabridin on PC and the involvement of ROS signaling. Intracellular ROS and mitochondrial ROS (mitoROS) production in PC cell lines, DU-145 and LNCaP, were measured by H2DCFDA and MitoSOX Red staining, respectively. MTT assay was used to analyze the cellular viability. EdU staining assay was conducted to analyze the cell proliferation. To analyze apoptotic rate, TUNEL assay was performed. Caspase-3 activity was detected to reflect cell apoptosis. Western blot was carried out to detect the expression levels of Akt and p-Akt. We found that intracellular ROS and mitoROS levels were dose-dependently upregulated after glabridin treatment in both DU-145 and LNCaP cells, which was reversed by the treatment of ROS inhibitor, N-acetyl-L-cysteine (NAC). Glabridin inhibited the cell viability and reduced the number of EdU-positive DU-145 and LNCaP cells, which were respectively proved by MTT assay and EdU staining assay. Glabridin promoted cell death with increased apoptotic rate and caspase-3 activity in DU-145 and LNCaP cells. The effects of glabridin on cell proliferation and apoptosis were reversed by NAC. Moreover, glabridin suppressed the ratio of p-Akt/Akt, while NAC mitigated the decreased p-Akt/Akt ratio. In addition, the effects of glabridin on cell proliferation and apoptosis were also attenuated by Akt activator, SC79. Collectively, our results demonstrated that glabridin suppressed proliferation and induced apoptosis in PC cells via regulating ROS-mediated PI3K/Akt pathway. These findings suggested that glabridin might hold a promising prospective as a therapeutic agent against PC.

Glabridin induces paraptosis-like cell death via ER stress in breast cancer cells

Glabridin, a polyphenolic flavonoid isolated from the root of the glycyrrhiza glabra, has been demonstrated to have anti-tumor properties in human malignancies. This study found that glabridin decreased the viability of human breast cancer MDA-MB-231 and MCF7 cells in a dose-dependent manner that was not involved in the caspase-3 cascade. Glabridin promoted the formation of extensive cytoplasmic vacuolation by increasing the expression of endoplasmic reticulum (ER) stress markers BiP, XBP1s, and CHOP. The transmission electron microscopy and fluorescence with the ER chaperon KDEL suggested that the vacuoles were derived from ER. Glabridin-induced vacuolation was blocked when protein synthesis was inhibited by cycloheximide, demonstrating that protein synthesis is crucial for this process. Furthermore, we determined that glabridin causes loss of mitochondrial membrane potential as well as the production of reactive oxygen species, both of which lead to mitochondrial dysfunction. These features are consistent with a kind of programmed cell death described as paraptosis. This work reports for the first time that glabridin could induce paraptosis-like cell death, which may give new therapeutic approaches for apoptosis-resistant breast cancers.

Deoxyshikonin Mediates Heme Oxygenase-1 Induction and Apoptotic Response via p38 Signaling in Tongue Cancer Cell Lines

Deoxyshikonin (DSK), a phytochemical constituent, has been documented to elicit various oncostatic properties alone or in combination with established therapeutics. However, its role in restraining oral squamous cell carcinoma (OSCC) is mostly unclear. Here, we examined the tumor-suppressive effect of DSK and explored the molecular mechanisms underlying DSK’s activities on controlling oral cancer. Our results showed that DSK dose-dependently lessened the cell viability of tongue cancer cell lines, involving induction of cell cycle arrest at the sub-G1 phase and apoptotic cell death. Moreover, a unique signature of apoptosis-related proteins, including augmented nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression and caspase activation, was observed in DSK-treated tongue cancer cell lines. Furthermore, DSK-mediated upregulation of HO-1 and cleavage of caspase-9 and -3 were significantly inhibited by pharmacological blockage of p38 kinase. Collectively, these data revealed that DSK halted cell cycle progression and elicited cell apoptosis in tongue cancer cell lines, reshaping a p38-dependent profile of apoptotic proteome. Our findings provided novel insights into the therapeutic implications of a natural compound on the management of OSCC.

Pharmacological Effects and Underlying Mechanisms of Licorice-Derived Flavonoids

Glycyrrhizae Radix et Rhizoma is the most frequently prescribed natural medicine in China and has been used for more than 2,000 years. The flavonoids of licorice have garnered considerable attention in recent decades due to their structural diversity and myriad pharmacological effects, especially as novel therapeutic agents against inflammation and cancer. Although many articles have been published to summarize different pharmacological activities of licorice in recent years, the systematic summary for flavonoid components is not comprehensive. Therefore, in this review, we summarized the pharmacological and mechanistic data from recent researches on licorice flavonoids and their bioactive components.

Glabratephrin reverses doxorubicin resistance in triple negative breast cancer by inhibiting P-glycoprotein

Triple-negative breast cancer is one of the most aggressive breast cancer. The first therapeutic option is chemotherapy, often based on anthracycline as doxorubicin. However, chemotherapy efficacy is limited in by the presence of P-glycoprotein (Pgp), a membrane transporter protein that effluxes doxorubicin, reducing its cellular accumulation and toxicity. Inhibiting Pgp activity with effective and non-toxic products is still an open challenge. In this work, we demonstrated that the natural product Glabratephrin (Glab), a prenylated flavonoid from Tephrosia purpurea with a unique chemical structure, increased doxorubicin accumulation and cytotoxicity in triple negative breast cancer cells with high levels of Pgp, characterized by both acquired or intrinsic resistance to doxorubicin. Glab also reduced the growth of Pgp-expressing tumors, without adding significant extra-toxicities to doxorubicin treatment. Interestingly, Glab did not change the expression of Pgp, but it reduced the affinity for Pgp and the efflux of doxorubicin, as suggested by the increased Km and the reduced Vmax. In silico molecular docking predicted that Glab binds two residues (phenylalanine 322, glutamine 721) localized in the transmembrane domains of Pgp, facing the extracellular environment. Moreover, site-directed mutagenesis identified glycine 185 as a critical residue mediating the reduced catalytic efficacy of Pgp elicited by Glab. We propose Glab as an effective and safe compound able to reverse doxorubicin resistance mediated by Pgp in triple negative breast cancers, opening the way to a new combinatorial approach that may improve chemotherapy efficacy in the most refractory and aggressive breast cancer.

Molecular mechanisms underlying the anticancer activities of licorice flavonoids

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice has been commonly used in traditional Chinese medicine for treatment of gastric, liver, and respiratory disease conditions for more than two thousand years. It is a major component of several Chinese patent medicines certificated by National Medical Products Administration that possess great anticancer activities.

AIM OF THE STUDY

To comprehensively summarize the anticancer activities of licorice flavonoids, explain the underlying molecular mechanisms, and assess their therapeutic potentials and side-effects.

METHODS

PubMed, Research Gate, Web of Science, Google Scholar, academic journals, and Science Direct were used as information sources, with the key words of "anticancer", "licorice", "flavonoids", and their combinations, mainly from 2000 to 2019.

RESULTS

Sixteen licorice flavonoids are found to possess anticancer activities. These flavonoids inhibit cancer cells through blocking cell cycle and regulating multiple signaling pathways. The major pathways targeted by licorice flavonoids include: the MAPK pathway, PI3K/AKT pathway, NF-κB pathway, death receptor - dependent extrinsic signaling pathway, and mitochondrial apoptotic pathway.

CONCLUSION

Licorice flavonoids are a group of versatile molecules that have pleiotropic effects on cell growth, survival and cell signaling. Many of the flavonoids possess inhibitory activities toward cancer cell growth and hence have a great therapeutic potential in cancer treatment. However, additional preclinical studies are still needed to assess their in vivo efficacy and possible toxicities. It is also imperative to evaluate the effects of licorice flavonoids on the metabolism of other drugs and explore the potential synergistic mechanism.

Toxicogenetic and antiproliferative effects of chrysin in urinary bladder cancer cells

The antitumour activity of chrysin have been studied in several types of cancer cells. In urinary bladder cancer, its cytotoxic effects have already demonstrated; however, its mechanism of action is not completely understood and the role of tumour protein p53 (TP53) gene in these effects is unclear. In this study, we investigated the role of chrysin (10, 20, 40, 60 80 and 100 µM) in progression of bladder tumour cells with different status of the TP53 gene and different degrees of tumour (RT4, grade 1, TP53 wild type; 5637, grade 2, TP53 mutated and T24, grade 3, TP53 mutated). Results demonstrated that chrysin inhibited cell proliferation by increasing reactive oxygen species and DNA damage and inhibited cell migration in all cell lines. In TP53 wild-type cells, a sub-G1 apoptotic population was present. In mutated TP53 cells, chrysin caused arrest at the G2/M phase and morphological changes accompanied by downregulation of PLK1, SRC and HOXB3 genes. In addition, in Grade 2 cells, chrysin induced global DNA hypermethylation and, in the highest-grade cells, downregulated c-MYC, FGFR3 and mTOR gene expression. In conclusion, chrysin has antiproliferative and toxicogenetic activity in bladder tumour cells independently of TP53 status; however, the mechanisms of action are dependent on TP53 status.

In-vitro antitumor activity of compounds from Glycyrrhiza glabra against C6 glioma cancer cells: identification of natural lead for further evaluation

A HP20 resin-based unique method was adopted to get an active fraction of the hydroalcoholic extract of G. glabra roots. The fraction showed potent cytotoxicity against cancer cell line and was further subjected to detailed phytochemical investigation to obtain ten biomarkers. The isolated compounds were also tested for the cytotoxicity against the C6 glioma cell line in vitro using MTT assay. Among the isolated compounds, glycyrrhetic acid (1), glabrol (6), and glabridin (9) exhibited significant cytotoxicity. The compounds showed a dose-dependent decrease in cell viability. The active compounds were subjected to molecular docking study against topoisomerase I and topoisomerase II to support the mechanism of antitumor activity.

Modulating effect of Coronarin D in 5-fluorouracil resistance human oral cancer cell lines induced apoptosis and cell cycle arrest through JNK1/2 signaling pathway

Coronarin D (CD) is one of the main components of Hedychium coronarium rhizome, which has therapeutic potential by reducing cell proliferation in cancer cells. However, the mechanism of CD to 5-fluorouracil (5FU) oral cancer cell remain unclearly. This study discusses the CD to 5FU chemoresistance oral squamous cell carcinoma (OSCC) biochemical mechanisms and possibly pathways to inhibit multiplication in oral cancer. The effect of CD-treated 5FU-chemoresistance human oral cancer cell lines were subjected to MTT assay, cell cycle assay, DAPI assay, annexin-V/PI double staining assay and mitochondrial membrane potential measurement. Furthermore, western blotting was performed to assess the effect of CD on the expression levels of apoptosis related protein and MAPK signaling pathway. The results of the study evidenced that CD reduced viability of 5FU cancer cells in a dose- and time-dependent manner compared with control. The cytotoxic effect of CD lead to cell cycle arrest in the G2/M phase and induced apoptosis in both internal and external pathways. CD induces apoptosis by enhancing phosphorylation of JNK, further exploring the combination of CD and SP600125 reduced the overexpression of phosphate JNK levels. The mechanism of action of CD in 5FU on human oral cancer cells is reported for the first time and can hopeful to be a potential therapeutic agent for 5FU against human oral cancer cells.

Coronarin D suppresses proliferation, invasion and migration of glioma cells via activating JNK signaling pathway

Coronarin D (CD) is one of the primary components of the Hedychium coronarium rhizomes and possesses strong anticancer effects via preventing cell growth in many cancer cells. The study was aimed to explore the molecular mechanisms underlying effects of CD on proliferation, invasion and migration of gliomas cells. Gliomas cell lines U251 was employed for detecting cells viability and proliferation by Cell Counting Kit-8 assay and colony formation assay. In addition, scratch wound healing and transwell assays were performed for the analysis of U251 cells invasion and migration respectively. Furthermore, the expression of p-Akt/Akt, p-p38/p38, p-ERK/ERK, p-JNK/JNK, p-STAT3/STAT3, cyclinE, cyclinD1, CTGF, MMP-2 and MMP-9 were measured by Western blotting. CD could suppress proliferation, invasion and migration of glioma cells and induced reduction of cyclinE, cyclinD1, CTGF, MMP-2 and MMP-9 expression via activating JNK signaling pathway. CD treatment suppressed expression of p-AKT, p38, and ERK and elevated expression of p-JNK in concentration- and time-dependent manners. Moreover, CD significantly induced reduction of phosphorylated STAT3 expression. Exposure of cells to the JNK-specific inhibitor SP600125 reduced the cytotoxicity effects of CD, combination of CD and SP600125 corrected overexpression of phosphorylated JNK and reduction of phosphorylated STAT3. Pretreatment of SP600125 also improves gliomas cells viability and invasion. The results revealed that CD may remarkably suppress gliomas cell growth through JNK and STAT3 signaling. In present study, these findings revealed that CD induces suppression of cell viability in gliomas cells and possesses therapeutic effect on gliomas.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

Lupiwighteone induces caspase-dependent and -independent apoptosis on human breast cancer cells via inhibiting PI3K/Akt/mTOR pathway

Breast cancer is one of the most common causes of mortality in women. Lupiwighteone has anticancer effects in prostate cancer cells and neuroblastoma cells. However, the molecular and cellular mechanisms of lupiwighteone effects on human breast cancer cells are not as well known. In the present study, we investigated the effects of lupiwighteone on the proliferation and apoptosis of two different human cancer cells; MCF-7, an estrogen receptor (ER)-positive human breast cancer cell, and MDA-MB-231, a triple negative human breast cancer cell. Lupiwighteone treatment decreased the viability of MCF-7 and MDA-MB-231 cells. Lupiwighteone treatment resulted in apoptotic cell death in breast cancer cells, which was characterized by DNA fragmentation, accumulation of apoptotic cells, and nuclear condensation. We also showed that treatment with lupiwighteone induced caspase-dependent apoptosis (up-regulation of caspase-3, -7, -8, -9, PARP, and Bax or down-regulation of Bid, Bcl-2), induction of caspase-independent apoptosis (up-regulation of AIF and Endo G on cytosol), and inhibition of the PI3K/Akt/mTOR signaling pathway (down-regulation of PI3K, p-Akt, and p-mTOR) in both MCF-7 and MDA-MB-231 cells. These results suggest that lupiwighteone induces caspase-dependent and -independent apoptosis in both breast cancer cell lines via inhibiting PI3K/Akt/mTOR pathway.

Antiproliferative and toxicogenomic effects of resveratrol in bladder cancer cells with different TP53 status

The antitumor activity of resveratrol, a polyphenolic compound found mainly in grapes, has been studied in several types of cancer. In bladder cancer, its antiproliferative effects have already been demonstrated; however, its mechanism of action is not completely understood. The aim of this study was to evaluate resveratrol antitumor activity (12.5, 25, 50, 100, 150, 200, and 250 μM) and its possible mechanisms of action in bladder tumor cells with different TP53 gene status (RT4, grade 1, TP53 wild type; 5637-grade 2 and T24-grade 3, TP53 mutated). Cell proliferation, clonogenic survival, morphological changes, cell cycle progression, apoptosis rates, genotoxicity, global methylation, immunocytochemistry for p53 and PCNA and relative expression profiles of the AKT, mTOR, RASSF1A, HOXB3, SRC, PLK1, and DNMT1 were evaluated. Resveratrol decreased cell proliferation and induced DNA damage in all cell lines. Regarding the long-term effects, resveratrol reduced the number of colonies in all cell lines; however, TP53 wild type cells were more resistant. Increased rates of apoptosis were found in the TP53 wild type cells and this was accompanied by AKT, mTOR, and SRC downregulation. In addition, the resveratrol antiproliferative effects in wild type TP53 cells were accompanied by modulation of the DNMT1 gene. In the TP53 mutated cells, cell cycle arrest at S phase with PLK1 downregulation was observed. Additionally, there was modulation of the HOXB3/RASSF1A pathway and nuclear PCNA reduction in the highest-grade cells. In conclusion, resveratrol has antiproliferative activity in bladder tumor cells; however, the mechanisms of action are dependent on TP53 status. Environ. Mol. Mutagen., 60:740-751, 2019. © 2019 Wiley Periodicals, Inc.

Glycyrrhiza glabra-Enhanced Extract and Adriamycin Antiproliferative Effect on PC-3 Prostate Cancer Cells

Prostate cancer is the second most commonly diagnosed cancer in men worldwide, which is almost incurable, once it progresses into the metastatic stage. Adriamycin (ADR) is a known chemotherapeutic agent that causes severe side effects. In recent years, studies in natural plant products have revealed their anticancer activities. In particular, Glycyrrhiza glabra enhanced extract (GGE), commonly known as licorice, has been reported to exert antiproliferative properties against cancer cells. In this study, the cytotoxic potential of GGE was assessed in PC-3 cells, when it is administrated alone or in combination with Adriamycin. PC-3 cells were treated with GGE and/or ADR, and the inhibition of cell proliferation was evaluated by the MTT assay. Cell cycle alterations and apoptosis rate were measured through flow cytometry. Expression levels of autophagy-related genes were evaluated with specific ELISA kits, Western blotting, and real-time PCR, while NMR spectrometry was used to identify the implication of specific metabolites. Our results demonstrated that GGE alone or in co-treatment with ADR shows antiproliferative properties against PC-3 cells, which are mediated by both apoptosis and autophagy mechanisms.

Targeting Cancer with Phytochemicals via Their Fine Tuning of the Cell Survival Signaling Pathways

The role of phytochemicals as potential prodrugs or therapeutic substances against tumors has come in the spotlight in the very recent years, thanks to the huge mass of encouraging and promising results of the in vitro activity of many phenolic compounds from plant raw extracts against many cancer cell lines. Little but important evidence can be retrieved from the clinical and nutritional scientific literature, where flavonoids are investigated as major pro-apoptotic and anti-metastatic compounds. However, the actual role of these compounds in cancer is still far to be fully elucidated. Many of these phytochemicals act in a pleiotropic and poorly specific manner, but, more importantly, they are able to tune the reactive oxygen species (ROS) signaling to activate a survival or a pro-autophagic and pro-apoptosis mechanism, depending on the oxidative stress-responsive endowment of the targeted cell. This review will try to focus on this issue.

An Intrinsic Mitochondrial Pathway Is Required for Phytic Acid-Chitosan-Iron Oxide Nanocomposite (Phy-CS-MNP) to Induce G₀/G₁ Cell Cycle Arrest and Apoptosis in the Human Colorectal Cancer (HT-29) Cell Line

Magnetic iron oxide nanoparticles are among the most useful metal nanoparticles in biomedical applications. A previous study had confirmed that phytic acid-chitosan-iron oxide nanocomposite (Phy-CS-MNP) exhibited antiproliferative activity towards human colorectal cancer (HT-29) cells. Hence, in this work, we explored the in vitro cytotoxicity activity and mechanistic action of Phy-CS-MNP nanocomposite in modulating gene and protein expression profiles in HT-29 cell lines. Cell cycle arrest and apoptosis were evaluated by NovoCyte Flow Cytometer. The mRNA changes (cyclin-dependent kinase 4 (Cdk4), vascular endothelial growth factor A (VEGFA), c-Jun N-terminal kinase 1 (JNK1), inducible nitric oxide synthase (iNOS), and matrix metallopeptidase 9 (MMP9)) and protein expression (nuclear factor-kappa B (NF-κB) and cytochrome c) were assessed by quantitative real-time polymerase chain reaction (PCR) and western blotting, respectively. The data from our study demonstrated that treatment with Phy-CS-MNP nanocomposite triggered apoptosis and G₀/G₁ cell cycle arrest. The transcriptional activity of JNK1 and iNOS was upregulated after treatment with 90 μg/mL Phy-CS-MNP nanocomposite. Our results suggested that Phy-CS-MNP nanocomposite induced apoptosis and cell cycle arrest via an intrinsic mitochondrial pathway through modulation of Bax and Bcl-2 and the release of cytochrome c from the mitochondria into the cytosol.

MicroRNA-520a suppresses HBV replication in HepG2.2.15 cells by inactivating AKT

Objective

To investigate whether the mechanism by which a microRNA, miR-520a, suppresses the replication of hepatitis B virus (HBV) involves the regulation of the serine/threonine kinase (AKT) gene.

Methods

The effects of miR-520a on the proliferation, mitotic index and apoptosis of the HBV-replicating human hepatocellular carcinoma cell line HepG2.2.15 were measured using standard laboratory methods including flow cytometry. The effects of miR-520a on HBV transcription and replication were assessed using methods including immunoassays and reverse transcription–polymerase chain reaction. The effect of small interfering RNA (siRNA) to AKT on the levels of AKT mRNA and protein were also evaluated.

Results

In HepG2.2.15 cells, miRNA-520a reduced HBV transcription and replication by reducing AKT levels. MiRNA-520a decreased cell proliferation and mitosis entry of cells and increased apoptosis in HepG2.2.15 cells. AKT levels were reduced significantly by its siRNA, which resulted in suppression of HBV replication in HepG2.2.15 cells.

Conclusions

MiRNA-520a inhibited AKT gene expression and suppressed HBV transcription and replication. These findings suggest that miRNA-520a may be a novel target for the treatment of HBV infection because miRNA-520a reduced HepG2.2.15 cell survival and inhibited HBV replication associated with the AKT signalling pathway.

Coronarin D induces apoptotic cell death through the JNK pathway in human hepatocellular carcinoma

Coronarin D, a diterpene derived from the rhizomes of Hedychium coronarium, has been used to treat inflammatory diseases. Coronarin D can exert strong anticancer effects through cell growth prevention and cell cycle arrest in many cancer cells. In this study, we investigated the molecular mechanism through which coronarin D suppresses cell proliferation and triggers cell death in human hepatocellular carcinoma (HCC) cells. Treatment of Huh7 and Sk-hep-1 cells with coronarin D resulted in a significantly increased loss of mitochondrial membrane potential, leading to the cleavage and activation of caspase-9, caspase-8, and caspase-3 and changes in Bax, Bcl-2, and Bcl-xL protein levels. Coronarin D significantly induced autophagy by increasing the expression of Beclin-1 and LC3-II and reducing the expression of p62. Moreover, Huh7 and Sk-hep-1 cells exposed to coronarin D had decreased expression of phosphorylated AKT, p38, and ERK and increased expression of phosphorylated JNK. Exposure of cells to the JNK-specific inhibitor SP600125 attenuated the apoptotic effects of coronarin D. Taken together, this is the first study to report that coronarin D may effectively inhibit cell growth through apoptosis. We have provided evidence indicating that coronarin D induces cell death through the upregulation of JNK mitogen-activated protein kinases in human HCC cells.