CIL-102 binds to tubulin at colchicine binding site and triggers apoptosis in MCF-7 cells by inducing monopolar and multinucleated cells

Heavy water (D2O) induces autophagy-dependent apoptotic cell death in non-small cell lung cancer A549 cells by generating reactive oxygen species (ROS) upon microtubule disruption

OBJECTIVE

Deuterium oxide (D2O) or heavy water is known to have diverse biological activities and have a few therapeutic applications due to its limited toxicity to human subjects. In the present study, we investigated the mechanism of D2O-induced cytotoxicity in non-small cell lung cancer A549 cells.

RESULTS

We found that D2O-treatment resulted in cytotoxicity, cell cycle arrest, and apoptosis in A549 cells in a dose-dependent fashion. In contrast, limited cytotoxicity was observed in lung fibroblasts WI38 cells. Moreover, D2O-treatment resulted in the disruption of the cellular microtubule network, accompanied by the generation of ROS. On further investigation, we observed that the intracellular ROS triggered autophagic responses in D2O-treated cells, leading to apoptosis by inhibiting the oncogenic PI3K/ Akt/ mTOR signaling. D2O-treatment was also found to enhance the efficacy of paclitaxel in A549 cells.

SIGNIFICANCE

D2O induces autophagy-dependent apoptosis in A549 cells via ROS generation upon microtubule depolymerization and inhibition of PI3K/ Akt/ mTOR signaling. It augments the efficacy of other microtubule-targeting anticancer drug taxol, which indicates the potential therapeutic importance of D2O as an anticancer agent either alone or in combination with other chemotherapeutic drugs.

New antiparasitic derivatives of the furoquinoline alkaloids kokusaginine and flindersiamine

In this work is reported the synthesis of 16 new compounds obtained from kokusaginine and flindersiamine, the main alkaloids isolated from the bark of Balfourodendron riedelianum . The activity of the compounds against axenic cultures of Trypanosoma cruzi epimastigtotes and trypomastigotes, as well as intracellular amastigotes, is described, together with their cytotoxic activity against three different human cell lines. The synthetic strategy for the preparation of the new compounds was based on the reactivity at the position C-4 of the furoquinoline core towards nucleophiles. The new derivatives were synthesized by a Buchwald-Hartwig reaction, in most cases under green, solvent free conditions. Compounds 1c and 1e displayed better in-vitro activity against trypomastigotes than benznidazole and nifurtimox (positive controls) with IC 50 < 4 µM. In addition, both compounds were not cytotoxic activity against the three human cell lines K562 (erytroleukimia), LM2 (breast cancer) and HaCat (keratinocyte). Interestingly, when evaluated against intracellular amastigotes, compound 1c was able to significantly reduce the number of this parasite form, compared to the negative control.

NMK-BH2, a novel microtubule-depolymerising bis (indolyl)-hydrazide-hydrazone, induces apoptotic and autophagic cell death in cervical cancer cells by binding to tubulin at colchicine - site

BACKGROUND

Microtubules, the key components of the eukaryotic cytoskeleton and mitotic spindle, are one of the most sought-after targets for cancer chemotherapy, especially due to their indispensible role in mitosis. Cervical cancer is a prevalent malignancy among women of developing countries including India. In spite of the remarkable therapeutic advancement, the non-specificity of chemotherapeutic drugs adversely affect the patients' survival and well-being, thus, necessitating the quest for novel indole-based anti-microtubule agent against cervical cancer, with high degree of potency and selectivity.

METHODS

For in vitro studies, we used MTT assay, confocal microscopy, fluorescence microscopy, flow cytometry and Western blot analysis. Study in cell free system was accomplished by spectrophotometry, fluorescence spectroscopy and TEM and computational analysis was done by AutodockTools 1.5.6.

RESULTS

NMK-BH2 exhibited significant and selective anti-proliferative activity against cervical cancer HeLa cells (IC₅₀ = 1.5 μM) over normal cells. It perturbed the cytoskeletal and spindle microtubules of HeLa cells leading to mitotic block and cell death by apoptosis and autophagy. Furthermore, NMK-BH2 targeted the tubulin-microtubule system through fast and strong binding to the αβ-tubulin heterodimers at colchicine-site.

CONCLUSION

This study identifies and characterises NMK-BH2 as a novel anti-microtubule agent and provides insights into its key anti-cancer mechanism through two different cell death pathways: apoptosis and autophagy, which are mutually independent.

GENERAL SIGNIFICANCE

It navigates the potential of the novel bis (indolyl)-hydrazide-hydrazone, NMK-BH2, to serve as lead for development of new generation microtubule-disrupting chemotherapeutic with improved efficacy and remarkable selectivity towards better cure of cervical cancer.

Design, synthesis and biological evaluation of flexible and rigid analogs of 4H-1,2,4-triazoles bearing 3,4,5-trimethoxyphenyl moiety as new antiproliferative agents

Several flexible and rigid analogs of 4H-1,2,4-triazoles (compounds 8a-g and 9a-g) bearing trimethoxyphenyl pharmacophoric unit, were designed and synthesized as potential anticancer agents. The in vitro cytotoxic assay indicated that both flexible and rigid analogs (8 and 9, respectively) can potentially inhibit the growth of cancerous cells (A549, MCF7, and SKOV3), with IC₅₀ values less than 5.0 µM. Furthermore, compounds 10a-l as regional isomers of compounds 9 exhibited remarkable cytotoxic activity with IC₅₀ values ranging from 0.30 to 5.0 µM. The rigid analogs 9a, 10h and 10k were significantly more potent than etoposide against MCF7, SKOV3 and A549 cells, respectively. These compounds showed high selectivity towards cancer cells over normal cells, as they had no significant cytotoxicity against L929 cells. In addition, the representative compounds 9a and 10h could inhibit the tubulin polymerization at micro-molar levels. By determining changes in the colchicine-tubulin fluorescence, it was suggested that compound 10h could bind to the tubulin at the colchicine pocket. The molecular docking study further confirmed the inhibitory activity of promising compounds 9a, 10h and 10k on tubulin polymerization through binding to the colchicine-binding site.

Novel CIL-102 derivatives as potential therapeutic agents for docetaxel-resistant prostate cancer

The standard-of-care treatment for metastatic prostate cancer (PCa) is androgen deprivation therapy (ADT). Nevertheless, most tumors eventually relapse and develop into lethal castration-resistant prostate cancer (CRPC). Docetaxel is a FDA-approved agent for the treatment of CRPC; however, the tumor often quickly develops resistance to this drug. Thus, there is an immediate need for novel therapies to treat docetaxel-resistant PCa. In this study, we modified the structure of CIL-102 and investigated the efficacy of the derivatives against CRPC and docetaxel-resistant PCa. These novel CIL-102 derivatives inhibit CRPC tumorigenicity, including proliferation, migration and colony formation, and importantly, selectively inhibit CRPC cell proliferation over non-cancerous prostate epithelia. Computational modeling indicated the derivatives bind to β-tubulin and immunocytochemistry revealed the depolymerization of microtubules upon treatment. Western blot analyses reveal that pro-apoptotic and anti-oxidant pathways are activated, and MitoSOX and DCF-DA analyses confirmed increased reactive oxygen species (ROS) production upon treatments. Furthermore, CIL-102 derivatives effectively reduce the proliferation of docetaxel-resistant CR PCa cell lines. Our data indicate the potential of these compounds as promising therapeutic agents for CRPC as well as docetaxel-resistant CRPC.

GTP-binding facilitates EB1 recruitment onto microtubules by relieving its auto-inhibition

Microtubule plus end-binding protein, EB1 is a key regulator of microtubule dynamics. Auto-inhibitory interaction in EB1 has previously been shown to inhibit its ability to bind to microtubules and regulate microtubule dynamics. However, the factors that promote its microtubule regulatory activity by over-coming the auto-inhibition are less known. Here, we show that GTP plays a critical role in promoting the microtubule-targeting activity of EB1 by suppressing its auto-inhibition. Our biophysical data demonstrate that GTP binds to EB1 at a distinct site in its conserved N-terminal domain. Detailed analyses reveal that GTP-binding suppresses the intra-molecular inhibitory interaction between the globular N-terminus and the C-terminal coiled-coil domain. We further show that mutation of the GTP-binding site residues in N-terminus weakens the affinity for GTP, but also for the C-terminus, indicating overlapping binding sites. Confocal imaging and biochemical analysis reveal that EB1 localization on the microtubules is significantly increased upon mutations of the GTP-binding site residues. The results demonstrate a unique role of GTP in facilitating EB1 interaction with the microtubules by relieving its intra-molecular inhibition. They also implicate that GTP-binding may regulate the functions of EB1 on the cellular microtubules.

The inhibitory effect of kokusaginine on the growth of human breast cancer cells and MDR-resistant cells is mediated by the inhibition of tubulin assembly

The emergence of multidrug resistance (MDR) is a significant challenge in breast carcinoma chemotherapy. Kokusaginine isolated from Dictamnus dasycarpus Turcz. has been reported to show cytotoxicity in several human cancer cell lines including breast cancer cells MCF-7. In this study, kokusaginine showed the potent inhibitory effect on MCF-7 multidrug resistant subline MCF-7/ADR and MDA-MB-231 multidrug resistant subline MDA-MB-231/ADR. Kokusaginine markedly induced apoptosis in a concentration-dependent manner in MCF-7/ADR cells. Furthermore, kokusaginine reduced P-gp mRNA and protein levels, and suppressed P-gp function especially in MCF-7/ADR cells. In addition, kokusaginine showed to inhibit tubulin assembly and the binding of colchicine to tubulin by binding directly to tubulin and affects tubulin formation in vitro. Taken together, these results support the potential therapeutic value of kokusaginine as an anti-MDR agent in chemotherapy for breast carcinoma.

Novel quinolone chalcones targeting colchicine-binding pocket kill multidrug-resistant cancer cells by inhibiting tubulin activity and MRP1 function

Agents targeting colchicine-binding pocket usually show a minimal drug-resistance issue, albeit often associated with high toxicity. Chalcone-based compounds, which may bind to colchicine-binding site, are found in many edible fruits, suggesting that they can be effective drugs with less toxicity. Therefore, we synthesized and examined 24 quinolone chalcone compounds, from which we identified ((E)-3-(3-(2-Methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-17) and ((E)-6-Methoxy-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one) (CTR-20) as promising leads. In particular, CTR-20 was effective against 65 different cancer cell lines originated from 12 different tissues, largely in a cancer cell-specific manner. We found that both CTR-17 and CTR-20 reversibly bind to the colchicine-binding pocket on β-tubulin. Interestingly however, both the CTRs were highly effective against multidrug-resistant cancer cells while colchicine, paclitaxel and vinblastine were not. Our study with CTR-20 showed that it overcomes multidrug-resistance through its ability to impede MRP1 function while maintaining strong inhibition against microtubule activity. Data from mice engrafted with the MDA-MB-231 triple-negative breast cancer cells showed that both CTR-17 and CTR-20 possess strong anticancer activity, alone or in combination with paclitaxel, without causing any notable side effects. Together, our data demonstrates that both the CTRs can be effective and safe drugs against many different cancers, especially against multidrug-resistant tumors.

A Novel Resveratrol Based Tubulin Inhibitor Induces Mitotic Arrest and Activates Apoptosis in Cancer Cells

Resveratrol is one of the most widely studied bioactive plant polyphenols which possesses anticancer properties. Previously we have reported synthesis, characterization and identification of a novel resveratrol analog, SS28. In the present study, we show that SS28 induced cytotoxicity in several cancer cell lines ex vivo with an IC₅₀ value of 3–5 μM. Mechanistic evaluation of effect of SS28 in non-small cell lung cancer cell line (A549) and T-cell leukemic cell line (CEM) showed that it inhibited Tubulin polymerization during cell division to cause cell cycle arrest at G2/M phase of the cell cycle at 12–18 h time period. Immunofluorescence studies confirmed the mitotic arrest upon treatment with SS28. Besides, we show that SS28 binds to Tubulin with a dissociation constant of 0.414 ± 0.11 μM. Further, SS28 treatment resulted in loss of mitochondrial membrane potential, activation of Caspase 9 and Caspase 3, leading to PARP-1 cleavage and finally cell death via intrinsic pathway of apoptosis. Importantly, treatment with SS28 resulted in regression of tumor in mice. Hence, our study reveals the antiproliferative activity of SS28 by disrupting microtubule dynamics by binding to its cellular target Tubulin and its potential to be developed as an anticancer molecule.

Novel chloroquinoline derivatives incorporating biologically active benzenesulfonamide moiety: synthesis, cytotoxic activity and molecular docking

Background

Quinoline derivatives have diverse biological activities including anticancer activity. On the other hand, many sulfonamide derivatives exhibited good cytotoxic activity. Hybrids of both moieties may present novel anticancer agents.

Results

Chloroquinoline incorporating a biologically active benzene-sulfonamide moieties 5–21 and diarylsulfone derivatives 22 and 23 were prepared using (E)-1-(4-((E)-7-chloro-1-methylquinolin-4(1H)-ylideneamino)phenyl)-3-(dimethyl-amino)prop-2-en-1-one 4 as strategic starting material. The structure of the newly synthesized compounds were confirmed by elemental analyses and spectral data. Compound 4 was confirmed by X-ray crystallographic analysis. The prepared compounds were evaluated for their anticancer activity against Lung, HeLa, Colorectal and breast cancer cell lines. Compounds 2, 4, 7, 11, 14 and 17 showed better or comparable activity to 2′, 7′-dichlorofluorescein (DCF) as reference drug. Molecular docking of the active compounds on the active site of PI3K enzyme was performed in order to explore the binding mode of the newly synthesized compounds.

Conclusion

Compounds 2, 4, 7, 11, 14 and 17 are novel quinoline derivatives that may represent good candidates for further evaluations as anticancer agents. The mechanism of action of these compounds could be through inhibition of PI3K enzyme.Graphical abstract

Human SAS-6 C-Terminus Nucleates and Promotes Microtubule Assembly in Vitro by Binding to Microtubules

Centrioles are essential components of the animal centrosome and play crucial roles in the formation of cilia and flagella. They are cylindrical structures composed of nine triplet microtubules organized around a central cartwheel. Recent studies have identified spindle assembly abnormal protein SAS-6 as a critical component necessary for formation of the cartwheel. However, the molecular details of how the cartwheel participates in centriolar microtubule assembly have not been clearly understood. In this report, we show that the C-terminal tail (residues 470-657) of human SAS-6, HsSAS-6 C, the region that has been shown to extend toward the centriolar wall where the microtubule triplets are organized, nucleated and induced microtubule polymerization in vitro. The N-terminus (residues 1-166) of HsSAS-6, the domain known to be involved in formation of the central hub of the cartwheel, did not, however, exert any effect on microtubule polymerization. HsSAS-6 C bound to the microtubules and localized along the lengths of the microtubules in vitro. Microtubule pull-down and coimmunoprecipitation (Co-IP) experiments with S-phase synchronized HeLa cell lysates showed that the endogenous HsSAS-6 coprecipitated with the microtubules, and it mediated interaction with tubulin. Isothermal calorimetry titration and size exclusion chromatography showed that HsSAS-6 C bound to the αβ-tubulin dimer in vitro. The results demonstrate that HsSAS-6 possesses an intrinsic microtubule assembly promoting activity and further implicate that its outer exposed C-terminal tail may play critical roles in microtubule assembly and stabilizing microtubule attachment with the centriolar cartwheel.

Distinct tubulin dynamics in cancer cells explored using a highly tubulin-specific fluorescent probe

A highly specific fluorescent probe (OC9) was discovered exhibiting tubulin-specific affinity fluorescence, which allowed selective labeling of cellular tubulin in microtubules. Moreover, distinct tubulin dynamics in various cellular bio-settings such as drug resistant or epithelial-mesenchymal transition (EMT) cancer cells were directly observed for the first time via OC9 staining.

Discovery of 3-phenylquinolinylchalcone derivatives as potent and selective anticancer agents against breast cancers

A number of 3-phenylquinolinylchalcone derivatives were synthesized and evaluated in vitro for their antiproliferative activities against three breast cancer cell lines (MCF-7, MDA-MB-231, and SKBR-3), and a non-cancer normal epithelial cell line (H184B5F5/M10). Among them, (E)-3-[3-(4-methoxyphenyl)quinolin-2-yl]-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (7) was active against the growth of MCF-7, MDA-MB-231, and SKBR-3 with IC50 values of 1.05, 0.75, and 0.78 μM respectively without significant cytotoxicity to the normal H184B5F5/M10 cell line and therefore, was selected as a new lead for further mechanism studies. Results indicated that compound 7 inhibited the polymerization of tubulins, induced G2/M cell cycle arrest via modulation of the cyclin B1, cdk1 and CDC25. Compound 7 ultimately induced cell apoptosis by the increase of apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2. In addition, PARP was cleaved while caspase-3 and -8 activities were induced after the treatment of compound 7 for 24 h in a concentration-dependent manner. Thus, compound 7 induces cell cycle arrest at G2/M phase via cleavage of PARP, induces caspase-3 and -8 activities and consequently to cause the cell death. Further study on the structure optimization of 7 is ongoing.

Thalidomide (5HPP-33) suppresses microtubule dynamics and depolymerizes the microtubule network by binding at the vinblastine binding site on tubulin

Thalidomides were initially thought to be broad-range drugs specifically for curing insomnia and relieving morning sickness in pregnant women. However, its use was discontinued because of a major drawback of causing teratogenicity. In this study, we found that a thalidomide derivative, 5-hydroxy-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (5HPP-33), inhibited the proliferation of MCF-7 with a half-maximal inhibitory concentration of 4.5 ± 0.4 μM. 5HPP-33 depolymerized microtubules and inhibited the reassembly of cold-depolymerized microtubules in MCF-7 cells. Using time-lapse imaging, the effect of 5HPP-33 on the dynamics of individual microtubules in live MCF-7 cells was analyzed. 5HPP-33 (5 μM) decreased the rates of growth and shortening excursions by 34 and 33%, respectively, and increased the time microtubules spent in the pause state by 92% as compared to that of the vehicle-treated MCF-7 cells. 5HPP-33 (5 μM) reduced the dynamicity of microtubules by 62% compared to the control. 5HPP-33 treatment reduced the distance between the two poles of a bipolar spindle, induced multipolarity in some of the treated cells, and blocked cells at mitosis. In vitro, 5HPP-33 bound to tubulin with a weak affinity. Vinblastine inhibited the binding of 5HPP-33 to tubulin, and 5HPP-33 inhibited the binding of BODIPY FL-vinblastine to tubulin. Further, a molecular docking analysis suggested that 5HPP-33 shares its binding site on tubulin with vinblastine. The results provided significant insight into the antimitotic mechanism of action of 5HPP-33 and also suggest a possible mechanism for the teratogenicity of thalidomides.

Drug–tubulin interactions interrogated by transient absorption spectroscopy

The triplet excited state of complexed COL and MTC gives well defined transient spectra undetectable in the absence of TU.

+TIP EB1 downregulates paclitaxel‑induced proliferation inhibition and apoptosis in breast cancer cells through inhibition of paclitaxel binding on microtubules

Microtubule plus‑end‑binding protein (+TIP) EB1 has been shown to be upregulated in breast cancer cells and promote breast tumor growth in vivo. However, its effect on the cellular actions of microtubule‑targeted drugs in breast cancer cells has remained poorly understood. By using cellular and biochemical assays, we demonstrate that EB1 plays a critical role in regulating the sensitivity of breast cancer cells to anti‑microtubule drug, paclitaxel (PTX). Cell viability assays revealed that EB1 expression in the breast cancer cell lines correlated with the reduction of their sensitivity to PTX. Knockdown of EB1 by enzymatically‑prepared siRNA pools (esiRNAs) increased PTX‑induced cytotoxicity and sensitized cells to PTX‑induced apoptosis in three breast cancer cell lines, MCF‑7, MDA MB‑231 and T47D. Apoptosis was associated with activation of caspase‑9 and an increase in the cleavage of poly(ADP‑ribose) polymerase (PARP). p53 and Bax were upregulated and Bcl2 was downregulated in the EB1‑depleted PTX‑treated MCF‑7 cells, indicating that the apoptosis occurs via a p53‑dependent pathway. Following its upregulation, the nuclear accumulation of p53 and its association with cellular microtubules were increased. EB1 depletion increased PTX‑induced microtubule bundling in the interphase cells and induced formation of multiple spindle foci with abnormally elongated spindles in the mitotic MCF‑7 cells, indicating that loss of EB1 promotes PTX‑induced stabilization of microtubules. EB1 inhibited PTX‑induced microtubule polymerization and diminished PTX binding to microtubules in vitro, suggesting that it modulates the binding sites of PTX at the growing microtubule ends. Results demonstrate that EB1 downregulates inhibition of PTX‑induced proliferation and apoptosis in breast cancer cells through a mechanism in which it impairs PTX‑mediated stabilization of microtubule polymerization and inhibits PTX binding on microtubules.

Microtubule +TIP protein EB1 binds to GTP and undergoes dissociation from dimer to monomer on binding GTP

The +TIP protein EB1 autonomously tracks the growing plus end of microtubules and regulates plus-end dynamics. Previous studies have indicated that EB1 can recognize GTP-bound tubulin structures at the plus end, and it localizes on the microtubule surface at a site close to the exchangeable GTP-binding site of tubulin. Although the GTP-dependent structural change in tubulin has been demonstrated to be a critical determinant for recognition of plus ends by EB1, the effect of GTP on the structure of EB1 has remained unclear. Here, we have used spectroscopic, calorimetric, and biochemical methods to analyze the effect of GTP on EB1 in vitro. Isothermal titration calorimetry and tryptophan fluorescence quenching experiments demonstrated that EB1 binds to GTP with a dissociation constant ~30 μM. Circular dichroism measurements showed that EB1 undergoes changes in its secondary structure on binding GTP. Size-exclusion chromatography and urea-induced unfolding analyses revealed that GTP binding induces dissociation of the EB1 dimer to monomers. Size-exclusion chromatography followed by biochemical analysis further determined that EB1-GTP binding involves association of approximately one molecule of GTP per EB1 monomer. The results reveal a hitherto unknown GTP-dependent mechanism of dimer-to-monomer transition in EB1 and further implicate its possible role in regulating the stability of the EB1 dimer vs monomer as well as plus-end regulation in cells.

Dinuclear Cu(I) complexes of pyridyl-diazadiphosphetidines and aminobis(phosphonite) ligands: synthesis, structural studies and antiproliferative activity towards human cervical, colon carcinoma and breast cancer cells

The copper(i) complexes containing phosphorus donor ligands such as diazadiphosphetidine, cis-{(o-OCH2C5H4N)P(μ-N(t)Bu)}2 (1) and aminobis(phosphonite), C6H5N{P(OC6H3(OMe-o)(C3H5-p))2}2 (2, PNP), have been synthesized. Treatment of 1 with copper iodide afforded the 1D coordination polymer [{Cu(μ-I)}2{(o-OCH2C5H4N)P(μ-N(t)Bu)}2]n (3). Treatment of 3 with 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) produced mixed-ligand complexes [(L)2Cu2{(o-OCH2C5H4N)P(μ-N(t)Bu)}2][I]2 (4 L = bpy; 5 L = phen) in good yields. The reaction of 2 with copper iodide yielded a rare tetranuclear copper complex [(CuI)2C6H5N(PR2)2]2 (6), which on subsequent treatment with various pyridyl ligands produced binuclear complexes [{Cu(μ-I)(py)}2(μ-PNP)] (7), [Cu2(μ-I)(bpy)2(μ-PNP)]I (8), [Cu2(μ-I)I(bpy)(μ-PNP)] (9), [Cu2(phen)(bpy)(μ-PNP)](OTf)2 (10), [Cu2(μ-I)I(phen)(μ-PNP)] (11) and [Cu2(μ-I)(phen)2(μ-PNP)]I (12), in an almost quantitative yield. The new copper(i) complexes (4, 5 and 7-12) were tested for anti-cancer activity against three human tumor cell lines. Compounds 5, 10 and 12 showed in vitro antitumor activity 5-7 fold higher than cisplatin, the most used anticancer drug. These three most potent compounds (5, 10 and 12) were chosen for detailed study to understand their mechanism of action. The copper(i) compounds studied in the present investigation were found to inhibit tumor cell growth by arresting cells at the S-phase of the cell cycle. The characteristic nuclear morphology of treated cells showed signs of DNA damage. The experimental evidence clearly indicated that these compounds initiated apoptosis, which is mediated through the p53 pathway.

Synthesis and evaluation of 2-heteroaryl and 2,3-diheteroaryl-1,4-naphthoquinones that potently induce apoptosis in cancer cells

This article describes the preparation of 2-heteroaryl and 600 dpi in TIF format)??>2,3-diheteroaryl-1,4-naphthoquinones by an environmentally benign short synthetic route with the goal of finding 1,4-naphthoquinone derivatives that induce apoptosis in cancer cells.