Colon Carcinoma Cell Line HCT116 Research Articles

Noninvasive visualization of tumor growth in a human colorectal liver metastases xenograft model using bioluminescence in vivo imaging

BackgroundBioluminescence imaging (BLI) is an ideal tool for noninvasive, quantitative monitoring of tumor progression/regression in animal models. The effectiveness of different treatment strategies is displayed by an altered intensity of bioluminescence, demonstrating a change of the tumor burden. The aim of this study was to establish a reliable, reproducible colorectal hepatic metastases cancer animal model. MethodsCells of the human colon carcinoma cell line HCT-116 Lucpos expressing the firefly luciferase enzyme gene were used. HCT-116 Lucpos cells (2.5 × 106) were injected through the portal vein into the liver of immunoincompetent nude mice. BLI was used to analyze intrahepatic tumor burden and growth kinetic. ResultsHCT-116 Lucpos cells demonstrated a progressive and reproducible growth in the liver after intraportal injection. Four days after injection, the animals were analyzed for tumor growth by BLI, and mice without or too low bioluminescence signals were excluded (between 10% and 20% animals). HCT-116 Lucpos intrahepatic tumors responded successfully to different dosages (5 and 10 mg/kg) of 5-fluorouracil. ConclusionsBLI is an important tool with many potential advantages for investigators. The measurement of intrahepatic tumor growth by imaging luciferase activity noninvasively provides valuable information on tumor burden and effectiveness of therapy. Thus, the presented intrahepatic metastases model based on the growth of HCT-116 Lucpos cells is suitable for in vivo testing of different cancer therapy strategies.

Transforming Growth Factor Beta Receptor 2 (TGFBR2) Changes Sialylation in the Microsatellite Unstable (MSI) Colorectal Cancer Cell Line HCT116

Aberrant glycosylation is a common feature of many malignancies including colorectal cancers (CRCs). About 15% of CRC show the microsatellite instability (MSI) phenotype that is associated with a high frequency of biallelic frameshift mutations in the A10 coding mononucleotide microsatellite of the transforming growth factor beta receptor 2 (TGFBR2) gene. If and how impaired TGFBR2 signaling in MSI CRC cells affects cell surface glycan pattern is largely unexplored. Here, we used the TGFBR2-deficient MSI colon carcinoma cell line HCT116 as a model system. Stable clones conferring doxycycline (dox)-inducible expression of a single copy wildtype TGFBR2 transgene were generated by recombinase-mediated cassette exchange (RMCE). In two independent clones, dox-inducible expression of wildtype TGFBR2 protein and reconstitution of its signaling function was shown. Metabolic labeling experiments using the tritiated sialic acid precursor N-acetyl-D-mannosamine (ManNAc) revealed a significant decline (∼30%) of its incorporation into newly synthesized sialoglycoproteins in a TGFBR2-dependent manner. In particular, we detected a significant decrease of sialylated ß1-integrin upon reconstituted TGFBR2 signaling which did not influence ß1-integrin protein turnover. Notably, TGFBR2 reconstitution did not affect the transcript levels of any of the known human sialyltransferases when examined by real-time RT- PCR analysis. These results suggest that reconstituted TGFBR2 signaling in an isogenic MSI cell line model system can modulate sialylation of cell surface proteins like ß1-integrin. Moreover, our model system will be suitable to uncover the underlying molecular mechanisms of altered MSI tumor glycobiology.

A human tRNA methyltransferase 9‐like protein prevents tumour growth by regulating LIN9 and HIF1‐α

Emerging evidence points to aberrant regulation of translation as a driver of cell transformation in cancer. Given the direct control of translation by tRNA modifications, tRNA modifying enzymes may function as regulators of cancer progression. Here, we show that a tRNA methyltransferase 9-like (hTRM9L/KIAA1456) mRNA is down-regulated in breast, bladder, colorectal, cervix and testicular carcinomas. In the aggressive SW620 and HCT116 colon carcinoma cell lines, hTRM9L is silenced and its re-expression and methyltransferase activity dramatically suppressed tumour growth in vivo. This growth inhibition was linked to decreased proliferation, senescence-like G0/G1-arrest and up-regulation of the RB interacting protein LIN9. Additionally, SW620 cells re-expressing hTRM9L did not respond to hypoxia via HIF1-α-dependent induction of GLUT1. Importantly, hTRM9L-negative tumours were highly sensitive to aminoglycoside antibiotics and this was associated with altered tRNA modification levels compared to antibiotic resistant hTRM9L-expressing SW620 cells. Our study links hTRM9L and tRNA modifications to inhibition of tumour growth via LIN9 and HIF1-α-dependent mechanisms. It also suggests that aminoglycoside antibiotics may be useful to treat hTRM9L-deficient tumours.

Synthesis, characterization, X-ray diffraction, antimicrobial and in vitro cytotoxicity studies of 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole

Abstract The synthesis, spectral characterization, crystal structure and antimicrobial activity of the novel synthetic molecule 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole, C29H48N4 has been reported. The structure has also been determined by X-ray diffraction technique using direct method and was refined on F2 by the full-matrix least-squares. Crystals are orthorhombic and their space group is P212121, with a = 7.230(3), b = 31.451(13), c = 11.974(5) (A), α = β = γ = 90°. It can be conveniently obtained by the reaction of 7-Oxostigmast-5-ene with hydrazoic acid. The molecule has also been screened for its possible in vitro antimicrobial activity against Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Staphylococcus epidermidis, Bacillus cereus, Corynebacterium xerosis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa (MTCC 424). Minimum inhibitory concentration (MIC) of the synthesized compound has also been evaluated. The highest activity is observed against C. xerosi and P. vulgaris. Moreover, the compound has also been screened for its in vitro cytotoxicity against human colon carcinoma cell line, HCT116 and human liver hepatocellular carcinoma cell line, HepG2, using doxorubicin as standard. On the basis of its IC50 values, 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole was found to inhibit the cancer cells effectively.

Synthesis and biological evaluation of imidazo[4,5-b]pyridine and 4-heteroaryl-pyrimidine derivatives as anti-cancer agents

A series of N-phenyl-imidazo[4,5-b]pyridin-2-amines, 4-indazolyl-N-phenylpyrimidin-2-amines and N-phenyl-4-pyrazolo[3,4-b]pyridin-pyrimidin-2-amines have been synthesized. Their anti-proliferative activities were tested in HCT-116 human colon carcinoma and MCF-7 breast carcinoma cell lines. Many exhibited potent anti-proliferative and CDK9 inhibitory activities. A lead compound 18b demonstrated the ability to reduce the level of Mcl-1 anti-apoptotic protein, to activate caspase 3/7 and induce cancer cell apoptosis.

Design, synthesis and anticancer activity of 1-acyl-3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives

A series of novel 1-acyl-3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives were designed and synthesized. These derivatives were initially evaluated for their in vitro anticancer activity against human colon carcinoma HCT-116 cell line, and compounds 11a, b were chosen for further evaluation their in vitro activity against other five human cancer cell lines. These results indicate that most of the target compounds have considerable in vitro anticancer activity. The most active compound 11a was found to be 4- to 28-fold more potent than (R)-roscovitine against six human cancer cell lines. In addition, compound 11a was assessed for its activity against 12 kinases, and then evaluated for its interaction mode by docking experiments with cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase-3β (GSK3β).

The chemopreventive agent ursodeoxycholic acid inhibits proliferation of colon carcinoma cells by suppressing c-Myc expression

Ursodeoxycholic acid (UDCA) can prevent chemical and colitis-associated colon carcinogenesis by unknown mechanism(s). One of the processes underlying the chemopreventive action could be the inhibition of proliferation by UDCA. To clarify the antiproliferative mechanism of UDCA, we used p53 wt colon carcinoma cell lines HCT8 and HCT116. UDCA-induced inhibition of proliferation was reversible and was associated with a decrease of the S-phase and an increase of G1 phase population, but not with apoptosis or senescence. The treatment suppressed the expression of c-Myc protein and, as a consequence, of several cell cycle regulatory molecules, including CDK4 and CDK6. Using the HCT8 cell line as a model, we show that UDCA suppresses c-Myc at the protein level. The suppression of c-Myc alone or a simultaneous suppression of CDK4 and of CDK6 kinase is sufficient to inhibit cell proliferation. In sum, we identified c-Myc as a primary UDCA target in colon carcinoma cells. The degradation of c-Myc protein decreases the expression of the cell cycle regulators CDK4 and CDK6, which reversibly slows down the cell cycle. The suppression of these proproliferatory molecules is the likely initial mechanism of antiproliferatory action of UDCA on colon cancer cells.

Synthesis, Spectral Characterization, andIn VitroCytotoxicity of N-2′-Hydroxyethyl-Substituted Azacholestanes Prepared from 6-Oxocholestanes by Modified Schmidt Reaction

The present paper reports the synthesis and spectroscopic characterization of few N-2′-hydroxyethyl-substituted azacholestanes using BF3-OEt2, TiCl4, SnCl4, and H2SO4as catalysts in moderate yields by a modified version of Schmidt reaction. A notable feature is the passivity of SnCl4in case of 3β-acetoxy-N-2′-hydroxyethyl-6-aza-B-homo-5α-cholestan-7-one and 3β-chloro-N-2′-hydroxyethyl-6-aza-B-homo-5α-cholestan-7-one. However, the reaction was unsuccessful in case of N-2′-Hydroxyethyl-6-aza-B-homo-5α-cholestan-7-one. Another striking aspect is the attainment of high yield in case of H2SO4as catalyst. The semisolid compounds are characterized using various spectroscopic techniques such as FT-IR,1H-NMR and mass spectra, and microanalytical data. A reaction mechanism has been proposed on the basis of previous studies. Moreover, the compounds have also been screened for theirin vitrocytotoxicity against human colon carcinoma cell line, HCT116, and human liver hepatocellular carcinoma cell line, HepG2, using doxorubicin as standard. On the basis of IC50values, 3β-chloro-N-2′-hydroxyethyl-6-aza-B-homo-5α-cholestan-7-one (5) was found to inhibit the cancer cells most effectively.

Luminmycins A–C, Cryptic Natural Products from Photorhabdus luminescens Identified by Heterologous Expression in Escherichia coli

The 18 kb "silent" luminmycin biosynthetic pathway from Photorhabdus luminescens was cloned into a vector by using the newly established linear-linear homologous recombination and successfully expressed in Escherichia coli. Luminmycins A-C (1-3) were isolated from the heterologous host, and their structures were elucidated using 2D NMR spectroscopy and HRESIMS. Luminmycin A is a deoxy derivative of the previously reported glidobactin A, while luminmycins B and C most likely represent its acyclic biosynthetic intermediates. Compound 1 showed cytotoxicity against the human colon carcinoma HCT-116 cell line with an IC(50) value of 91.8 nM, while acyclic 2 was inactive at concentrations as high as 100 μg/mL.

Synthesis and photodynamic activity of a panel of BODIPY dyes

Eight BODIPY dyes were synthesized and used as photosensitizers (PSs) on the human colon carcinoma cell line HCT116. In this panel of molecules, the structure varies in the substituents on pyrrole 2, 6 positions and on the phenyl ring at the indacene 8 position. For these compounds relevant physico-chemical parameters, such as singlet oxygen production, fluorescent quantum yield, absorbance profile and a relative rank of lipophilicity were determined.Our results indicate that some of these novel PSs are very effective in reducing the growth/viability of HCT116 cells when irradiated with a green LED source, whereas they are practically devoid of activity in the dark, up to 5μM. To evaluate whether cell death is induced under these conditions, flow cytometric analysis of the percentage of apoptotic and autophagic cells was performed on four molecules, chosen for their efficacy/structural characteristics. Our data indicate that phototoxicity likely occurs mainly through apoptotic cell death, whereas autophagy seems to play a minor role in determining cell fate. Furthermore, the relationship between singlet oxygen generation and the PS efficacy is confirmed, thus underscoring the importance of the heavy-atom effect and of the presence of an aryl substituent at dipyrromethene 8 (meso) position.Among the PSs here described, the most efficient BODIPY was successfully tested on three other human cancer cell lines of different tissue origin, MCF7 (breast), A2780 and A2780/CP8 (ovary, sensitive and resistant to cisplatin, respectively), yielding IC50 values comparable to those obtained on HCT116.

Cytotoxic properties of platinum(IV) and dinuclear platinum(II) complexes and their ligand substitution reactions with guanosine-5′-monophosphate

The substitution reaction of the Pt(IV) complex [PtCl4(bipy)] with guanosine-5′-monophosphate (5′-GMP) was studied by UV–Vis spectrophotometry. This reaction was investigated under pseudo-first-order conditions at 37 °C in 25 mM Hepes buffer (pH = 7.2) in the presence of 10 mM NaCl to prevent the hydrolysis of the complex. The substitution of chlorides in [{trans-Pt(NH3)2Cl}2(μ-1,2-bis(4-pyridyl)ethane)](ClO4)2 (Pt3) complex by 5′-GMP was followed by 1H NMR spectroscopy under second-order conditions. Very similar values for the rate constants of both substitution steps were obtained. The Pt(IV) complexes, [PtCl4(bipy)] and [PtCl4(dach)], as well as dinuclaer Pt(II) [{trans-Pt(NH3)2Cl}2(μ-pyrazine)](ClO4)2 (Pt1), [{trans-Pt(NH3)2Cl}2(μ-4,4′-bipyridyl)](ClO4)2 · DMF (Pt2) and [{trans-Pt(NH3)2Cl}2(μ-1,2-bis(4-pyridyl)ethane)](ClO4)2 (Pt3) complexes, displayed potent cytotoxic activity against human ovarium carcinoma cell line TOV21G and lower activity toward human colon carcinoma HCT116 cell line at the same concentrations. Our data indicate that these platinum complexes could be explored further, as potential therapeutic agents for ovarian cancer.

Effects of hyperthermia on Hsp27 (HSPB1), Hsp72 (HSPA1A) and DNA repair proteins hMLH1 and hMSH2 in human colorectal cancer hMLH1-deficient and hMLH1-proficient cell lines

Purpose: The objective of the present study was to examine the consequences of a mild hyperthermia in human tumour cell lines deficient and proficient in the DNA mismatch repair system (MMR) to advance our understanding on the relationship between MMR and heat shock proteins (HSPs).Materials and methods: The human colon carcinoma cell lines HCT116 (parent cells), HCT116 + ch2 (MMR-deficient), and HCT116 + ch3 (MMR-proficient) were used. Cells were incubated at 41°C and 42°C for 1 h and then at 37°C for 4 and 24 h. The expression of Hsp27 and Hsp72 was evaluated by immunocytochemistry. Hsp27, Hsp72, hMLH1 and hMSH2 levels were assessed by western blotting in nuclear and cytoplasmic fractions. The alkaline comet assay was used to evaluate the DNA damage.Results: The mild hyperthermia significantly increased the protein expression levels of Hsp27 and Hsp72 in all cell lines, which was higher in the cytoplasm and nucleus of HCT116 + ch3 cells. We also observed that heat induced translocation of hMLH1 and hMSH2 proteins from the nucleus to the cytoplasm in HCT116 + ch3 cells. The comet assay revealed that HCT116 parent cells were more resistant to heat-induced DNA damage. However, the MMR-proficient and deficient cell lines repaired the DNA damage at the same rate.Conclusions: The present study demonstrates that hyperthermia induced the nuclear accumulation of Hsp27 and Hsp72 and affected the subcellular localisation of hMLH1 and hMSH2 in HCT116 + ch3 cells. Our findings suggest that the MMR system is not a direct determining factor for the different heat shock response in HCT116 cells.

Abstract 1085: TGFBR2-dependent alterations of glycosylation in MSI colorectal cancer

Abstract Aberrant glycosylation is a common feature of many malignancies including colorectal cancers. About 15% of colorectal cancers show the microsatellite instability (MSI) phenotype that is associated with a high frequency of biallelic frameshift mutations in the exon 3 coding mononucleotide microsatellite of the Transforming growth factor beta receptor 2 (TGFBR2) gene. If and how disruption of normal TGFBR2 signaling in these MSI colorectal cancer cells is linked to altered glycan pattern is largely unexplored. To address this issue we used the TGFBR2-deficient MSI colon carcinoma cell line HCT116 as a model system. Stable clones enabling doxycycline-inducible expression of wildtype TGFBR2 transgene were generated by recombinase-mediated cassette exchange (RMCE). In two independent clones dox-inducible expression of wildtype TGFBR2 protein and functional reconstitution of TGFBR2-mediated signal transduction as recognized by target gene regulation (SMAD7, SERPINE, c-myc) and Phospho-SMAD2 analysis was confirmed by Western blot and qRT-PCR analysis. Metabolic labeling experiments using the sialic acid precursor 3H-N-acetyl-mannosamine revealed a significant decline of 30% and hence newly synthesized sialoglycoproteins in TGFBR2 expressing cells. Therefore, our findings demonstrate that this model system can be used as a versatile tool to study TGFBR2-dependent effects. Furthermore, our data reveal a TGFBR2 gene-dependent aberrant glycosylation pattern in the MSI colon cell line HCT116. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1085. doi:1538-7445.AM2012-1085

Synthesis of Novel 6-(4-Substituted piperazine-1-yl)-9-(β-d-ribofuranosyl)purine Derivatives, Which Lead to Senescence-Induced Cell Death in Liver Cancer Cells

Novel purine ribonucleoside analogues (9-13) containing a 4-substituted piperazine in the substituent at N(6) were synthesized and evaluated for their cytotoxicity on Huh7, HepG2, FOCUS, Mahlavu liver, MCF7 breast, and HCT116 colon carcinoma cell lines. The purine nucleoside analogues were analyzed initially by an anticancer drug-screening method based on a sulforhodamine B assay. Two nucleoside derivatives with promising cytotoxic activities (11 and 12) were further analyzed on the hepatoma cells. The N(6)-(4-Trifluoromethylphenyl)piperazine analogue 11 displayed the best antitumor activity, with IC(50) values between 5.2 and 9.2 μM. Similar to previously described nucleoside analogues, compound 11 also interferes with cellular ATP reserves, possibly through influencing cellular kinase activities. Furthermore, the novel nucleoside analogue 11 was shown to induce senescence-associated cell death, as demonstrated by the SAβ-gal assay. The senescence-dependent cytotoxic effect of 11 was also confirmed through phosphorylation of the Rb protein by p15(INK4b) overexpression in the presence of this compound.

Pro-oxidative effects of melanoidin–copper complexes on isolated and cellular DNA

High molecular weight Maillard reaction products (melanoidins) are described to possess metal-chelating properties. Whereas in food systems, this ability contributes to antioxidant properties, the consequences on biological systems are not quite clear. The study was aimed to evaluate the implication of metal complexation by melanoidins on DNA damage. Melanoidins prepared with d-glucose and different l-amino acids under water-free reaction conditions were charged with cupric ions. The effect on isolated DNA was investigated by the PM2 assay and on cellular systems in the human colon carcinoma cell line HCT-116 by alkaline unwinding. Independent of the amino acid composition, pure melanoidins (MW >14 kDa) did not cause significant DNA damage. By charging melanoidins with Cu2+ ions, a considerable DNA strand breaking activity was detectable, which was again amplified in an oxidative milieu (addition of hydrogen peroxide). Since Cu2+ normally does not provoke the formation of reactive oxygen species (ROS) via Fenton-type reaction, the results obtained have to be attributed to reducing properties of melanoidins. Thus, in melanoidin–copper complexes redox cycling may take place leading to Cu+ which subsequently undergoes Fenton-type and Haber–Weiss reactions. As a consequence, ROS are formed, which may explain the generation of DNA strand breaks.

Involvement of mitochondria-mediated apoptosis in deoxynivalenol cytotoxicity

Deoxynivalenol (DON) is a widespread trichothecene mycotoxin which contaminates cereal crops and harmfully affects the gastrointestinal tract. Since it is well known that mitochondria play a central role in apoptosis triggered by many stimuli, an effort was made to examine whether DON-induced cytotoxicity occurs through mitochondria-mediated apoptotic pathway. The intestinal system being one of the primary targets of mycotoxins, the human colon carcinoma cell line HCT116 was used in this study. Using flow cytometric analyses and immunofluorescence, we showed that DON at 100μM induced a mitochondria-dependent apoptotic pathway associated with opening of the mitochondrial permeability transition pore (PTP), loss of the mitochondrial transmembrane potential (ΔΨm), downstream generation of O2− and cytochrome c release. The DON-induced apoptosis was accompanied by an activation of caspase 9 and 3, as demonstrated by Western blot and caspase activity assay. In addition, by taking advantage of HCT116 cells invalidated for Bax, we showed that this pro-apoptotic protein favored mitochondrial alterations induced by the mycotoxin. Besides, incubation of purified mitochondria with DON indicated that this mycotoxin does not directly target mitochondria to induce PTP-dependent permeabilization of mitochondrial membranes. Altogether, our results indicate that mitochondria-related caspase-dependent apoptotic pathway is involved in this in vitro model of DON induced-cytotoxicity.

5-aza-2'-deoxycytidine-induced inhibition of CDH13 expression and its inhibitory effect on methylation status in human colon cancer cells in vitro and on growth of xenograft in nude mice

To determine the inhibitory effect of 5-aza-2'-deoxycytidine (5-Aza-CdR) on the growth of human colon carcinoma cells and xenografts in nude mice, to observe its effect on CDH13 gene expression and methylation in the xenografts, and to explore the possible mechanisms. Human colon carcinoma cell line HCT116 cells were treated with 5-Aza-CdR, and the cell morphology was observe by phase contrast microscopy. The cell growth was assessed by MTT assay. A tumor-bearing mouse model was generated by subcutaneous inoculation of human colon carcinoma HCT116 cells into nude mice. The tumor growth in the nude mice was observed, the CDH13 gene expression and its methylation status in the tumors were detected using methylation specific PCR (MSP), RT-PCR, Western blotting and immunohistochemistry. After treatment with 5-Aza-CdR, the inhibition rate of the growth of cultured HCT116 cells was increased as the concentration was increasing. The growth of the xenografts in nude mice was significantly inhibited, and the methylated CDH13 gene was reactivated. After 4 weeks of 5-Aza-CdR treatment, no significant difference was found between the body weights of nude mice in the 5-Aza-CdR group [(18.06 ± 1.29) g] and control group [(17.07 ± 0.84) g], (P > 0.10), and the average volume of xenografts of the 5-Aza-CdR group was (907.00 ± 87.29) mm(3), significantly smaller than the (1370.93 ± 130.20) mm(3) in the control group (P < 0.005). No expression of CDH13 gene was found in the control group. The expression of CDH13 gene in the 5-Aza-CdR group was increased along with the increasing concentration of 5-Aza-CdR. 5-Aza-CdR inhibits the growth of human colon cancer cells in culture and in nude mice, and induces the cancer cells to re-express CDH13 in nude mice. Its mechanism may be that demethylation of the methylated CDH13 promoter induced by 5-Aza-CdR restores CDH13 expression and thus inhibits the tumor growth in nude mice.

Platinum(ii/iv) complexes containing ethylenediamine-N,N′-di-2/3-propionate ester ligands induced caspase-dependent apoptosis in cisplatin-resistant colon cancer cells

Several new R(2)eddp (R = i-Pr, i-Bu; eddp = ethylenediamine-N,N'-di-3-propionate) esters and corresponding platinum(ii) and platinum(iv) complexes of the general formula [PtCl(n)(R(2)edda-type)] (n = 2, 4) were synthesized and characterized by spectroscopic methods (IR, (1)H and (13)C NMR) and elemental analysis. The crystal structure of platinum(iv) complex [PtCl(4){(c-Pe)(2)eddip}] (3a) was resolved and is given herein. Ligand precursors, platinum(ii), and platinum(iv) complexes were tested against eight tumor cell lines (CT26CL25, HTC116, SW620, PC3, LNCaP, U251, A375, and B16). Selectivity in the action of those compounds between tumor and two normal primary cells (fibroblasts and keratinocytes) are discussed. A structure-activity relationship of these compounds is discussed. Furthermore, cell cycle distribution, induction of necrosis, apoptosis, autophagy, anoikis, caspase activation, ROS, and RNS are presented on the cisplatin-resistant colon carcinoma HCT116 cell line.

Multiple antitumor effects of picropodophyllin in colon carcinoma cell lines: Clinical implications

Although colorectal cancer can be successfully treated by conventional strategies such as chemo/radiotherapy and surgery, a substantial number of cases, in particular those with liver metastases, remain incurable. Therefore, novel treatment approaches are warranted. The IGF-1R and its ligands, mainly IGF-1 and IGF-2, have been suggested to play pivotal roles in proliferation, survival and migration of adenocarcinoma cells of the colon/rectum. Therefore, interference with IGF-1R-mediated signaling may represent a therapeutic option for this malignancy. In this study, semi-quantitative RT-PCR analyses of 48 paired, colorectal cancer patient samples showed significant overexpression of tumor IGF-1R and IGF-2 mRNA. There was also an overexpression of MMP-7, which was significantly correlated with histopathological parameters. Based on these findings, the effect of the IGF-1R-inhibitory cyclolignan picropodophyllin (PPP) was assessed in the four colon carcinoma cell lines HT-29, HCT-116, DLD-1 and CaCO-2. PPP strongly and dose-dependently inhibited proliferation and migration in all cell lines. However, when exposed to 0.5 μM PPP, only HT-29 showed a net decrease of viable cells as compared with the cell number at the beginning of the experiment, a finding that coincided with decreased expression/phosphorylation of IGF-1R, AKT and ERK. This cell line also exhibited PPP-induced downregulation of MMP-7 and MMP-9. Similar to the DLD-1 and HCT-116 cell lines, HT-29 also showed substantial cell detachment in response to PPP. Although a net reduction of cells by PPP seems to require a synchronized downregulation of IGF-1R, AKT and ERK1/2, part of the antitumor effect may be explained by other, possibly IGF-1R-unrelated mechanism(s). Such a multitude of inhibitory effects of PPP in colon cancer cells together with its low toxicity in vivo makes it a promising drug candidate in the treatment of this disease.

Coding genes join the non‐coding world

Coding genes join the non‐coding world