Phyotochemical candidates repurposing for cancer therapy and their molecular mechanisms.

Though limited success through chemotherapy, radiotherapy and surgery has been obtained for efficient cancer therapy for modern decades, cancers are still considered high burden to human health worldwide to date. Recently repurposing drugs are attractive with lower cost and shorter time compared to classical drug discovery, just as Metformin from Galega officinalis, originally approved for treating Type 2 diabetes by FDA, is globally valued at millions of US dollars for cancer therapy. As most previous reviews focused on FDA approved drugs and synthetic agents, current review discussed the anticancer potential of phytochemicals originally approved for treatment of cardiovascular diseases, diabetes, infectious diarrhea, depression and malaria with their molecular mechanisms and efficacies and suggested future research perspectives.

Molecular networks of FOXP family: dual biologic functions, interplay with other molecules and clinical implications in cancer progression.

Though Forkhead box P (FOXP) transcription factors comprising of FOXP1, FOXP2, FOXP3 and FOXP4 are involved in the embryonic development, immune disorders and cancer progression, the underlying function of FOXP3 targeting CD4 + CD25+ regulatory T (Treg) cells and the dual roles of FOXP proteins as an oncogene or a tumor suppressor are unclear and controversial in cancers to date. Thus, the present review highlighted research history, dual roles of FOXP proteins as a tumor suppressor or an oncogene, their molecular networks with other proteins and noncoding RNAs, cellular immunotherapy targeting FOXP3, and clinical implications in cancer progression.

Intraoperative OCT for surgical microscope with sensitivity drop and depth of focus correction based on variable focus and dynamic reference.

We have developed a surgical microscope-integrated optical coherence tomography (MI-OCT) system based on an active feedback method to obtain uniform optimal OCT image contrast along the depth of focus (DOF) of a surgical microscope. Conventional MI-OCT systems use a shorter DOF objective lens than those of surgical microscopes for OCT imaging. The existing MI-OCT system was developed to overcome sensitivity roll-off by using an electrically tunable lens (ETL). However, active change in the focus position through the ETL cannot cope with the sensitivity decrease due to optical path length difference (OPD) mismatch. The proposed active feedback method was able to maintain high sensitivity by actively performing OPD matching using a linear motor in the reference arm while tuning the focal position in the sample arm using the ETL. The optical system designed to maintain the OCT resolution and a retroreflector used for ensuring regular reflection intensity in the reference arm during OPD compensation contributed to the uniform sensitivity and stable OCT imaging performance. The simultaneous and automatic actuation of the ETL and linear motor provided sensitivity variation of 3 dB from 17 dB for 10-mm sample displacement corresponding to the DOF of the surgical microscope used in the MI-OCT system. By using an infrared detection card and a mouse brain tumor model, it was demonstrated that the proposed MI-OCT system could acquire OCT images with optimal sensitivity without the limitations due to short OCT DOF.

Correction to: Regulation of SIRT1/AMPK axis is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in hepatocellular carcinoma cells.

This article contains an error.

Regulation of SIRT1/AMPK axis is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is one of the most fatal malignancies with high mortality worldwide. Here the underlying antitumor mechanism of gallotannin was elucidated in HCC cells. Gallotannin suppressed viability and colony formation, increased subG1 portion and also induced senescence via upregulation of p21, G0/G1 arrest and higher SA-ß-gal activity in HepG2 and SK-Hep1 cells. However, pan-caspase inhibitor Z-VAD-FMK reversed the ability of gallotannin to activate caspase 3 at 48 h after treatment in two HCC cells. Of note, gallotannin also induced autophagic features by increasing LC3 punctae, LC3B-II conversion, autophagic vacuoles and decreasing the expression of Beclin1 in two HCC cells. Furthermore, autophagy flux assay using GFP-mRFP-LC3 plasmid revealed increased yellowish color and late autophagy inhibitor CQ or NH4Cl enhanced cytotoxicity, LC3B-II conversion, and LC3 punctae in gallotannin-treated HepG2 and SK-Hep1 cells compared to early autophagy inhibitor 3-MA or wortmannin. Interestingly, gallotannin attenuated the expression of SIRT1 and mTOR and activated phosphorylation of AMPK in two HCC cells. Furthermore, AMPK activator AICAR significantly enhanced SA-ß-gal activity and antiproliferation induced by gallotannin, while AMPK inhibitor compound C did not in two HCC cells. Consistently, LC3B-II conversion by gallotannin was not shown in AMPKα1 -/- MEF cells compared to WT AMPK +/+ MEF cells. Consistently, gallotannin reduced in vivo growth of HepG2 cells implanted in NCr nude mice along with decreased expression of PCNA and SIRT1 and increased AMPKα1 and TUNEL. Overall, these findings highlight evidence that regulation of SIRT1/AMPK is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in HCC cells.

The Anti-Wrinkle Mechanism of Melatonin in UVB Treated HaCaT Keratinocytes and Hairless Mice via Inhibition of ROS and Sonic Hedgehog Mediated Inflammatory Proteins.

Though melatonin is known to improve ultraviolet B (UVB)-induced oxidative damage and inflammatory conditions via the blockade of the nuclear factor (NF)-κB, interleukin (IL)-6, there is no report on the anti-wrinkle effect of melatonin to date. Hence in the present study, the anti-wrinkle mechanism of melatonin was elucidated in UVB treated HaCaT keratinocytes and hairless mice. Herein melatonin protected against a radical initiator tert-Butyl hydroperoxide (t-BOOH) induced reactive oxygen species (ROS) production, matrix metalloprotease 1 (MMP-1), pro-collagen and cytotoxicity in HaCaT keratinocytes. Additionally, melatonin suppressed the expression of sonic hedgehog (SHH) and GLI1 for hedgehog signaling and p-NF-κB, cyclooxygenase (COX-2), phospho-extracellular signal-regulated kinase-1 (p-ERK) for inflammatory responses in UVB treated HaCaT keratinocytes. Furthermore, melatonin protected skin from wrinkle formation, transdermal water loss in hairless mice irradiated by UVB for 8 weeks. Notably, melatonin prevented against epidermal thickness and dermal collagen degradation in UVB irradiated hairless mice by Hematoxylin and Eosin and Masson’s trichrome staining. Taken together, these findings suggest that melatonin reduces wrinkle formation via inhibition of ROS/SHH and inflammatory proteins such as NF-κB/COX-2/ERK/MMP1.

Apoptotic Effect of Astragalin in Melanoma Skin Cancers via Activation of Caspases and Inhibition of Sry-related HMg-Box Gene 10.

Though Astragalin (kaempferol-3-glucoside) contained in Paeonia lactiflora and other plants was known to have anti-oxidant, antiinflammatory, and anti-tumor activity, the anti-tumor mechanism of Astragalin has never been reported in melanomas until now. Thus, in the present study, the underlying apoptotic mechanism of Astragalin isolated from Aceriphyllum rossii was elucidated in A375P and SK-MEL-2 melanoma cells. Astragalin exerted cytotoxicity in A375P and SK-MEL-2 cells in a concentration-dependent manner. Also, Astragalin significantly increased the number of TdT-mediated dUTP nick end labeling positive cells and sub-G1 population as a feature of apoptosis in A375P and SK-MEL-2 cells compared with untreated control. Consistently, western blotting revealed that Astragalin activated caspase 9/3 and Bax, cleaved poly (ADP-ribose) polymerase, and attenuated the expression of cyclin D1, Mcl-1, and Sry-related HMg-Box gene 10 (SOX10) in A375P and SK-MEL-2 cells. Of note, ectopic expression of SOX10 reduced the apoptotic ability of Astragalin to inhibit proliferation, cleave poly (ADP-ribose) polymerase, and caspase 3 in A375P and SK-MEL-2 melanoma cells. Overall, our findings provide evidence that Astragalin induces apoptosis in A375P and SK-MEL-2 melanoma cells via activation of caspase9/3 and inhibition of SOX10 signaling. Copyright © 2017 John Wiley & Sons, Ltd.

Apoptotic Effect of Sanggenol L via Caspase Activation and Inhibition of NF-κB Signaling in Ovarian Cancer Cells.

In the present study, the underlying apoptotic mechanism of sanggenol L was elucidated in ovarian cancer cells. Sanggenol L showed cytotoxic and antiproliferative effect in A2780, SKOV-3, and OVCAR-3 ovarian cancer cells in a concentration-dependent fashion. Consistently, sanggenol L increased sub-G1 phase population and early and late apoptotic portion in ovarian cancer cells. Also, sanggenol L activated caspase9/3, suppressed the phosphorylation of IκBα and p65 NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), attenuated the expression of Cyclin D1, and cleaved poly(adenosine diphosphate ribose -ribose) polymerase in SKOV-3, A2780, and OVCAR-3 cells. Furthermore, sanggenol L blocked nuclear translocation of NF-κB and also attenuated the expression of NF-κB related genes such as c-Myc, Cyclin D1, and Bcl-X L, Bcl-2, in lipopolysaccharide-treated SKOV-3 cells. Overall, our findings for the first time suggest that sanggenol L induces apoptosis via caspase activation and inhibition of NF-κB/IκBα phosphorylation as a potent chemotherapeutic agent for ovarian cancers.

Grifola frondosa Extract Containing Bioactive Components Blocks Skin Fibroblastic Inflammation and Cytotoxicity Caused by Endocrine Disrupting Chemical, Bisphenol A.

Grifola frondosa (GF), a species of Basidiomycotina, is widely distributed across Asia and has been used as an immunomodulatory, anti-bacterial, and anti-cancer agent. In the present study, the pharmacological activity of the GF extract against an ecotoxicological industrial chemical, bisphenol A (BPA) in normal human dermal fibroblasts (NHDFs), was investigated. GF extract containing naringin, hesperidin, chlorogenic acid, and kaempferol showed an inhibitory effect on cell death and inflammation induced by BPA in the NHDFs. For the cell death caused by BPA, GF extract inhibited the production of reactive oxygen species responsible for the unique activation of the extracellular signal-regulated kinase. In addition, GF extract attenuated the expression of apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) and the pro-inflammatory cytokine IL-1ß by the suppression of the redox-sensitive transcription factor, nuclear factor-kappa B (NF-κB) in BPA-treated NHDFs. For the inflammation triggered by BPA, GF extract blocked the inflammasome-mediated caspase-1 activation that leads to the secretion of IL-1ß protein. These results indicate that the GF extract is a functional antioxidant that prevents skin fibroblastic pyroptosis induced by BPA.

UBE2M Drives Hepatocellular Cancer Progression as a p53 Negative Regulator by Binding to MDM2 and Ribosomal Protein L11.

Though UBE2M, an E2 NEDD8-conjugating enzyme, is overexpressed in HepG2, Hep3B, Huh7 and PLC/PRF5 HCCs with poor prognosis by human tissue array and TCGA analysis, its underlying oncogenic mechanism remains unclear. Herein, UBE2M depletion suppressed viability and proliferation and induced cell cycle arrest and apoptosis via cleavages of PARP and caspase 3 and upregulation of p53, Bax and PUMA in HepG2, Huh7 and Hep3B cells. Furthermore, UBE2M depletion activated p53 expression and stability, while the ectopic expression of UBE2M disturbed p53 activation and enhanced degradation of exogenous p53 mediated by MDM2 in HepG2 cells. Interestingly, UBE2M binds to MDM2 or ribosomal protein L11, but not p53 in HepG2 cells, despite crosstalk between p53 and UBE2M. Consistently, the colocalization between UBE2M and MDM2 was observed by immunofluorescence. Notably, L11 was required in p53 activation by UBE2M depletion. Furthermore, UBE2M depletion retarded the growth of HepG2 cells in athymic nude mice along with elevated p53. Overall, these findings suggest that UBE2M promotes cancer progression as a p53 negative regulator by binding to MDM2 and ribosomal protein L11 in HCCs.

Colocalization of MID1IP1 and c-Myc is Critically Involved in Liver Cancer Growth via Regulation of Ribosomal Protein L5 and L11 and CNOT2.

Though midline1 interacting protein 1 (MID1IP1) was known as one of the glucose-responsive genes regulated by carbohydrate response element binding protein (ChREBP), the underlying mechanisms for its oncogenic role were never explored. Thus, in the present study, the underlying molecular mechanism of MID1P1 was elucidated mainly in HepG2 and Huh7 hepatocellular carcinoma cells (HCCs). MID1IP1 was highly expressed in HepG2, Huh7, SK-Hep1, PLC/PRF5, and immortalized hepatocyte LX-2 cells more than in normal hepatocyte AML-12 cells. MID1IP1 depletion reduced the viability and the number of colonies and also increased sub G1 population and the number of TUNEL-positive cells in HepG2 and Huh7 cells. Consistently, MID1IP1 depletion attenuated pro-poly (ADP-ribose) polymerase (pro-PARP), c-Myc and activated p21, while MID1IP1 overexpression activated c-Myc and reduced p21. Furthermore, MID1IP1 depletion synergistically attenuated c-Myc stability in HepG2 and Huh7 cells. Of note, MID1IP1 depletion upregulated the expression of ribosomal protein L5 or L11, while loss of L5 or L11 rescued c-Myc in MID1IP1 depleted HepG2 and Huh7 cells. Interestingly, tissue array showed that the overexpression of MID1IP1 was colocalized with c-Myc in human HCC tissues, which was verified in HepG2 and Huh7 cells by Immunofluorescence. Notably, depletion of CCR4-NOT2 (CNOT2) with adipogenic activity enhanced the antitumor effect of MID1IP1 depletion to reduce c-Myc, procaspase 3 and pro-PARP in HepG2, Huh7 and HCT116 cells. Overall, these findings provide novel insight that MID1IP1 promotes the growth of liver cancer via colocalization with c-Myc mediated by ribosomal proteins L5 and L11 and CNOT2 as a potent oncogenic molecule.

p53-Dependent Apoptotic Effect of Puromycin via Binding of Ribosomal Protein L5 and L11 to MDM2 and its Combination Effect with RITA or Doxorubicin.

Among ribosomal proteins essential for protein synthesis, the functions of ribosomal protein L5 (RPL5) and RPL11 still remain unclear to date. Here, the roles of RPL5 and RPL11 were investigated in association with p53/p21 signaling in the antitumor effect of puromycin mainly in HCT116 and H1299 cancer cells. Cell proliferation assays using 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays and colony formation assays, cell cycle analysis, Reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were performed in cancer cells. Puromycin exerted cytotoxic and anti-proliferative effects in p53 wild-type HCT116 more than in p53 null H1299 cells. Consistently, puromycin increased sub-G1, cleaved Poly (ADP-ribose) polymerase (PARP), activated p53, p21, and Mouse double minute 2 homolog (MDM2), and attenuated expression of c-Myc in HCT116 cells. Notably, puromycin upregulated the expression of RPL5 and RPL11 to directly bind to MDM2 in HCT116 cells. Conversely, deletion of RPL5 and RPL11 blocked the activation of p53, p21, and MDM2 in HCT116 cells. Also, puromycin enhanced the antitumor effect with reactivating p53 and inducing tumor apoptosis (RITA) or doxorubicin in HCT116 cells. These findings suggest that puromycin induces p53-dependent apoptosis via upregulation of RPL5 or RPL11 for binding with MDM2, and so can be used more effectively in p53 wild-type cancers by combination with RITA or doxorubicin.

NEDD9 Inhibition by miR-25-5p Activation Is Critically Involved in Co-Treatment of Melatonin- and Pterostilbene-Induced Apoptosis in Colorectal Cancer Cells.

The underlying interaction between melatonin (MLT) and daily fruit intake still remains unclear to date, despite multibiological effects of MLT. Herein, the apoptotic mechanism by co-treatment of MLT and pterostilbene (Ptero) contained mainly in grape and blueberries was elucidated in colorectal cancers (CRCs). MLT and Ptero co-treatment (MLT+Ptero) showed synergistic cytotoxicity compared with MLT or Ptero alone, reduced the number of colonies and Ki67 expression, and also increased terminal deoxynucleotidyl transferase dUTP nick end labeling- (TUNEL) positive cells and reactive oxygen species (ROS) production in CRCs. Consistently, MLT+Ptero cleaved caspase 3 and poly (ADP-ribose) polymerase (PARP), activated sex-determining region Y-Box10 (SOX10), and also attenuated the expression of Bcl-xL, neural precursor cell expressed developmentally downregulated protein 9 (NEDD9), and SOX9 in CRCs. Additionally, MLT+Ptero induced differentially expressed microRNAs (upregulation: miR-25-5p, miR-542-5p, miR-711, miR-4725-3p, and miR-4484; downregulation: miR-4504, miR-668-3p, miR-3121-5p, miR-195-3p, and miR-5194) in HT29 cells. Consistently, MLT +Ptero upregulated miR-25-5p at mRNA level and conversely NEDD9 overexpression or miR-25-5p inhibitor reversed the ability of MLT+Ptero to increase cytotoxicity, suppress colony formation, and cleave PARP in CRCs. Furthermore, immunofluorescence confirmed miR-25-5p inhibitor reversed the reduced fluorescence of NEDD9 and increased SOX10 by MLT+Ptero in HT29 cells. Taken together, our findings provided evidence that MLT+Ptero enhances apoptosis via miR-25-5p mediated NEDD9 inhibition in colon cancer cells as a potent strategy for colorectal cancer therapy.

The Pivotal Role of Long Noncoding RNA RAB5IF in the Proliferation of Hepatocellular Carcinoma Via LGR5 Mediated ß-Catenin and c-Myc Signaling.

In the current study, the function of long noncoding RNA (LncRNA) RAB5IF was elucidated in hepatocellular carcinoma (HCCs) in association with LGR5 related signaling. Here TCGA analysis revealed that LncRNA RAB5IF was overexpressed in HCC, and its overexpression level was significantly (p < 0.05) correlated with poor prognosis in patients with HCC. Furthermore, LncRNA RAB5IF depletion suppressed cell proliferation and colony formation, increased sub G1 population, cleavage of poly ADP-ribose polymerase (PARP) and cysteine aspartyl-specific protease (caspase 3) and attenuated the expression of procaspase 3, pro-PARP and B-cell lymphoma 2 (Bcl-2) in HepG2 and Hep3B cells. Furthermore, LncRNA RAB5IF depletion reduced the expression of LGR5 and its downstreams such as ß-catenin and c-Myc in HepG2 and Hep3B cells. Notably, LGR5 depletion also attenuated the expression of pro-PARP, pro-caspase3, ß-catenin and c-Myc in HepG2 and Hep3B cells. Conversely, LGR5 overexpression upregulated ß-catenin and c-Myc in Alpha Mouse Liver 12 (AML-12) normal hepatocytes. Overall, these findings provide novel evidence that LncRNA RAB5IF promotes the growth of hepatocellular carcinoma cells via LGR5 mediated ß-catenin and c-Myc signaling as a potent oncogenic target.

Inhibition of JAK2/STAT3 and activation of caspase­9/3 are involved in KYS05090S­induced apoptosis in ovarian cancer cells.

To overcome the poor prognosis of patients with ovarian cancer, attempting to target ovarian cancer with effective antitumor compounds has been conducted for numerous years. Although the 3,4­dihydroquinazoline derivative KYS05090S was known to exert antitumor effects in A549 and ovarian cancer cells by inhibition of T­type Ca2+ channels, the complete underlying antitumor mechanism of this compound remains unclear. Thus, in the present study, the potential apoptotic mechanism of KYS05090S was elucidated in SKOV3 and OVCAR3 ovarian cancer cells. KYS05090S exerted significant cytotoxicity in SKOV3 and OVCAR3 ovarian cancer cells, and also increased the number of apoptotic bodies, and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and the sub­G1 population as a feature of apoptosis. Consistently, KYS05090S induced cleavage of poly(ADP­ribose) polymerase and caspase­9/3 in ovarian cancer cells. Notably, KYS05090S attenuated the expression of anti­apoptotic proteins, including cyclin D1 and B­cell lymphoma­2 (Bcl­2), and reduced the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in ovarian cancer cells. Additionally, KYS05090S blocked the nuclear translocation of STAT3 and suppressed the signaling of JAK2/STAT3 in interleukin­6­treated SKOV3 cells, as a STAT3 activator. Overall, these observations indicated that inhibition of JAK2/STAT3 signaling and activation of caspase­9/3 are critically involved in the effects of KYS05090S on apoptosis in ovarian cancer types, and the compound may be beneficial as a potent antitumor agent.

CNOT2 Is Critically Involved in Atorvastatin Induced Apoptotic and Autophagic Cell Death in Non-Small Cell Lung Cancers.

Though Atorvastatin has been used as a hypolipidemic agent, its anticancer mechanisms for repurposing are not fully understood so far. Thus, in the current study, its apoptotic and autophagic mechanisms were investigated in non-small cell lung cancers (NSCLCs). Atorvastatin increased cytotoxicity, sub G1 population, the number of apoptotic bodies, cleaved poly (ADP-ribose) polymerase (PARP) and caspase 3 and activated p53 in H1299, H596, and H460 cells. Notably, Atorvastatin inhibited the expression of c-Myc and induced ribosomal protein L5 and L11, but depletion of L5 reduced PARP cleavages induced by Atorvastatin rather than L11 in H1299 cells. Also, Atorvastatin increased autophagy microtubule-associated protein 1A/1B-light chain 3II (LC3 II) conversion, p62/sequestosome 1 (SQSTM1) accumulation with increased number of LC3II puncta in H1299 cells. However, late stage autophagy inhibitor chloroquine (CQ) increased cytotoxicity in Atorvastatin treated H1299 cells compared to early stage autophagy inhibitor 3-methyladenine (3-MA). Furthermore, autophagic flux assay using RFP-GFP-LC3 constructs and Lysotracker Red or acridine orange-staining demonstrated that autophagosome-lysosome fusion is blocked by Atorvastatin treatment in H1299 cells. Conversely, overexpression of CCR4-NOT transcription complex subunit 2(CNOT2) weakly reversed the ability of Atorvastatin to increase cytotoxicity, sub G1 population, cleavages of PARP and caspase 3, LC3II conversion and p62/SQSTM1 accumulation in H1299 cells. In contrast, CNOT2 depletion enhanced cleavages of PARP and caspase 3, LC3 conversion and p62/SQSTM1 accumulation in Atorvastatin treated H1299 cells. Overall, these findings suggest that CNOT2 signaling is critically involved in Atorvastatin induced apoptotic and autophagic cell death in NSCLCs.

Caspase inhibitors: a review of recently patented compounds (2013-2015).

INTRODUCTION: Although many caspase inhibitors have been patented, caspase inhibitors have not entered the market due to their toxicity and poor pharmacokinetic profile. AREAS COVERED: In this article, we review patents (2013-2015) for peptide and non-peptide caspase inhibitors and their compositions. EXPERT OPINION: Noteworthy patents include a peptidic caspase-2 inhibitor for nasal administration and a peptidomimetic caspase-6 inhibitor that can be administered via several routes for the treatment of neurodegenerative diseases. Furthermore, caspase-1 inhibitors for contact dermatitis and inflammation, cardiovascular diseases, and liver diseases and a caspase-3 inhibitor for cerebral stroke have been patented. Of particular interest is the novel use of tyrosine kinase inhibitors (sunitinib and its derivatives) for the prevention and treatment of age-related ocular diseases via inhibition of the caspase-3, dual-leucine zipper kinase (DLK) and leucine zipper-bearing kinase (LZK) pathways. However, for effective clinical application of caspase inhibitors, novel peptidic and nonpeptidic caspase inhibitors with lower toxicity and improved efficacy should be developed via structural modifications, and further animal studies and preclinical and clinical trials are needed. In addition, the poor pharmacokinetic properties of classic caspase inhibitors may be improved by using advanced drug delivery systems that employ liposomes, polymers, and nanoparticles through effective administration routes.

Reactive Oxygen Species and p53 Mediated Activation of p38 and Caspases is Critically Involved in Kaempferol Induced Apoptosis in Colorectal Cancer Cells.

Here the molecular mechanisms of Kaempferol were examined in colorectal cancers (CRCs). Kaempferol significantly exerted antiproliferative and cytotoxic effect in HCT116, HCT15, and SW480 cells. Also, Kaempferol increased sub G1 population, G2/M arrest, and the numbers of TUNEL cells in HCT116 colorectal cancer cells. Also, Kaempferol increased the PARP cleavages and activation of caspase-8, -9, and -3, phospho-p38 MAPK, p53, and p21 in HCT116 and HCT15 cells. Of note, Kaempferol generated reactive oxygen species (ROS) (43.7 ± 0.56 vs 25.8 ± 0.43, P < 0.01) in HCT116 cells and reversely ROS inhibitor NAC obstructed the effects of Kaempferol to cleave PARP and caspase-3 and activate phosphorylation of p38 MAPK in HCT116 colorectal cancer cells. Likewise, pancaspase inhibitor z-vad-fmk, p38 MAPK inhibitor SB203580, and p53 depletion blocked PARP and caspase-3 in Kaempferol treated HCT116 colorectal cancer cells. Therefore, these findings provide novel insight that ROS and p53 signalings mediate p38 phosphorylation and caspase activation in Kaempferol stimulated apoptosis in CRCs.

Reactive oxygen species dependent phosphorylation of the liver kinase B1/AMP activated protein kinase/ acetyl-CoA carboxylase signaling is critically involved in apoptotic effect of lambertianic acid in hepatocellular carcinoma cells.

Though lambertianic acid (LA) is reported to have hypolipidemic activity in liver, its underlying anticancer mechanism is poorly understood so far. Thus, in the present study, apoptotic mechanism of LA was elucidated in HepG2 and SK-Hep1 hepatocellular carcinoma (HCC) cells. Here LA increased cytotoxicity, sub-G1 population and Annexin V/PI positive cells in two HCC cells. Also, LA cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP), activated phosphorylation of liver kinase B1 (LKB1)/AMP activated protein kinase (AMPK)/ acetyl-CoA carboxylase (ACC) pathway and also suppressed antiapoptotic proteins such as phosphorylation of Akt/ mammalian target of rapamycin (mTOR) and the expression of B cell lymphoma-2 (Bcl-2)/ B-cell lymphoma-extra large (Bcl-xL) and cyclooxygenase-2 (COX-2) in two HCC cells. Furthermore, LA generated reactive oxygen species (ROS) in HepG2 cells and AMPK inhibitor compound C or ROS inhibitor N-acetyl-L-cysteine (NAC) blocked the apoptotic ability of LA to cleave PARP or increase sub G1 population in HepG2 cells. Consistently, cleavages of PARP and caspase-3 were induced by LA only in AMPK+/+ MEF cells, but not in AMPK-/- MEF cells. Also, immunoprecipitation (IP) revealed that phosphorylation of LKB1/AMPK through their binding was enhanced in LA treated HepG2 cells. Overall, these findings suggest that ROS dependent phosphorylation of LKB1/AMPK/ACC signaling is critically involved in LA induced apoptosis in HCCs.

Implications of Bcl-2 and its interplay with other molecules and signaling pathways in prostate cancer progression.

INTRODUCTION: Among several genetic alterations involved in the progression of prostate cancer, B cell lymphoma gene number 2 (BCL-2) is an important target molecule in the progression of androgen-independent prostate cancer (AIPC) after androgen ablation or castration. Nevertheless, the molecular mechanism of BCL-2 in prostate cancer progression remains elusive and controversial. In the current review, we discuss the critical role of BCL-2 in the carcinogenesis of prostate cancer with experimental evidences on the BCL-2 molecular networks in AIPC and androgen-dependent prostate cancer (ADPC) and subsequently suggest perspective research targeting BCL-2. Areas covered: This review focused on the molecular implications of BCL-2 in association with other molecules and signaling pathways involved in the progression and carcinogenesis of prostate cancer. Expert opinion: BCL-2 plays a pivotal role in the progression of AIPC than in ADPC since androgen represses BCL-2. BCL-2 acts as a pro-survival molecule in association with androgen-related signaling in the progression of ADPC, while BCL-2 upregulation, PTEN loss, PI3K/AKT phosphorylation and receptor tyrosine kinase (RTK) activation are primarily involved in AIPC. To identify more effective prostate cancer therapy, further mechanistic studies are required with BCL-2 inhibitors in AIPC and ADPC, considering a multi-target therapy against BCL-2 and its related signaling.