HT-29 Human Colorectal Carcinoma Research Articles

Inducing Immunogenic Cancer Cell Death through Oxygen‐Economized Photodynamic Therapy with Nitric Oxide‐Releasing Photosensitizers

Photodynamic therapy (PDT) utilizes reactive oxygen species (ROS) for eradication of cancer cells. Its effectiveness is governed by the oxygen content, which is scarce in the hypoxic tumor microenvironment. We report herein two zinc(II) phthalocyanines substituted with two or four nitric oxide (NO)‐releasing moieties, namely ZnPc‐2NO and ZnPc‐4NO, which can suppress the mitochondrial respiration, thereby sparing more intracellular oxygen for PDT. Using HT29 human colorectal adenocarcinoma cells and A549 human lung carcinoma cells, we have demonstrated that both conjugates release NO upon interaction with the intracellular glutathione, which can reduce the cellular oxygen consumption rate and adenosine triphosphate generation and alter the mitochondrial membrane potential. They can also relieve the hypoxic status of cancer cells and decrease the expression of hypoxia‐inducible factor protein HIF‐1α. Upon light irradiation, both conjugates can generate ROS and induce cytotoxicity even under a hypoxic condition, overcoming the oxygen‐dependent nature of PDT. Interestingly, the photodynamic action of ZnPc‐2NO elicits the release of damage‐associated molecular patterns, inducing the maturation of dendritic cells and triggering an antitumor immune response. The immunogenic cell death caused by this oxygen‐economized PDT has been demonstrated through a series of in vitro and in vivo experiments.

Inducing Immunogenic Cancer Cell Death through Oxygen-Economized Photodynamic Therapy with Nitric Oxide-Releasing Photosensitizers.

Photodynamic therapy (PDT) utilizes reactive oxygen species (ROS) for eradication of cancer cells. Its effectiveness is governed by the oxygen content, which is scarce in the hypoxic tumor microenvironment. We report herein two zinc(II) phthalocyanines substituted with two or four nitric oxide (NO)-releasing moieties, namely ZnPc-2NO and ZnPc-4NO, which can suppress the mitochondrial respiration, thereby sparing more intracellular oxygen for PDT. Using HT29 human colorectal adenocarcinoma cells and A549 human lung carcinoma cells, we have demonstrated that both conjugates release NO upon interaction with the intracellular glutathione, which can reduce the cellular oxygen consumption rate and adenosine triphosphate generation and alter the mitochondrial membrane potential. They can also relieve the hypoxic status of cancer cells and decrease the expression of hypoxia-inducible factor protein HIF-1α. Upon light irradiation, both conjugates can generate ROS and induce cytotoxicity even under a hypoxic condition, overcoming the oxygen-dependent nature of PDT. Interestingly, the photodynamic action of ZnPc-2NO elicits the release of damage-associated molecular patterns, inducing the maturation of dendritic cells and triggering an antitumor immune response. The immunogenic cell death caused by this oxygen-economized PDT has been demonstrated through a series of in vitro and in vivo experiments.

Design, synthesis, and biological evaluation of tetrahydroisoquinoline stilbene derivatives as potential antitumor candidates.

Herein, a novel class of tetrahydroisoquinoline stilbene derivatives were synthesized, and their potential in vitro anticancer activities were evaluated. Most of the compounds displayed inhibitory activity against one or more representative human cancer cell lines (lung cancer A549 cells, breast cancer MCF-7 cells, and human colorectal carcinoma HT-29 cells), especially compound 16e, which exhibited outstanding cytotoxicity to A549 cells. The tubulin polymerization assay demonstrated that compound 16e displayed better inhibition than colchicine when tested at the same concentration. It was found that 16e arrested A549 cells in G2/M phase by downregulating the expression of cell division cycle 2 (Cdc2) and upregulating the expression of proliferating cell nuclear antigen (PCNA) and cyclin B1. Flow cytometry and Western blot analysis indicated that 16e caused apoptosis via the mitochondrial-dependent apoptotic pathway by reducing mitochondrial membrane potential, inducing ROS accumulation, promoting the release of cytochrome C from the mitochondria into the cytoplasm, and further increasing the protein level of cleaved caspase-3. This work may inspire new ideas for the further improvement of tubulin-related anticancer drugs and treatments.

New Bioactive Polyacetylenes from the Marine Sponge Petrosia sp.

Three new polyacetylenes, pellynols P (1), Q (2), and R (3) were isolated from the marine sponge Petrosia sp., along with the known compound pellynol H (4). Their structures were determined by analyses of extensive NMR, HR-MS, and ESI-MS/MS data. All compounds displayed potent cytotoxicities against human hepatocellular carcinoma HepG2, human melanoma A375, and human colorectal carcinoma HT29 cell lines with IC50 values at the range of 1.4-4.4 μM.

Co-delivery of quercetin and caffeic-acid phenethyl ester by polymeric nanoparticles for improved antitumor efficacy in colon cancer cells

Aim This study aimed to synthesise quercetin- caffeic-acid phenethyl ester (CAPE)-co-loaded poly(lactic-co-glycolic-acid) (PLGA) nanoparticles (QuCaNP) and investigate their anti-cancer activity on human colorectal carcinoma HT-29 cells. Methods QuCaNPs were synthesised using single-emulsion (o/w) solvent evaporation method. Particle size, zeta potential, polydispersity index, in vitro release profile, and surface morphology of QuCaNPs were determined. Cytotoxicity, anti-migration, anti-proliferation and apoptotic activities of QuCaNPs were studied. Results Mean diameter of QuCaNP was 237.8 ± 9.670 nm, with a polydispersity index (PDI) of 0.340 ± 0.027. Encapsulation efficiency was 74.28% (quercetin) and 65.24% (CAPE). Particle size and drug content of QuCaNP remained stable for 30 days at −20 °C. The half-maximal inhibitory concentration (IC50) values of QuCaNP-treated HT-29 cells were calculated as 11.2 µg/mL (24 h) and 8.2 µg/mL (48 h). QuCaNP treatment increased mRNA levels of caspase-3 (2.38 fold) and caspase-9 (2-fold) and expressions of key proteins in the intrinsic apoptosis pathway in HT-29 cells. Conclusion Overall, our results demonstrated QuCaNPs exhibits improved anti-cancer activity on HT-29 cells.

Targeting oncogenic mutations in colorectal cancer using cryptotanshinone.

Colorectal cancer (CRC) is one of the most prevalent types of cancer in the world and ranks second in cancer deaths in the US. Despite the recent improvements in screening and treatment, the number of deaths associated with CRC is still very significant. The complexities involved in CRC therapy stem from multiple oncogenic mutations and crosstalk between abnormal pathways. This calls for using advanced molecular genetics to understand the underlying pathway interactions responsible for this cancer. In this paper, we construct the CRC pathway from the literature and using an existing public dataset on healthy vs tumor colon cells, we identify the genes and pathways that are mutated and are possibly responsible for the disease progression. We then introduce drugs in the CRC pathway, and using a boolean modeling technique, we deduce the drug combinations that produce maximum cell death. Our theoretical simulations demonstrate the effectiveness of Cryptotanshinone, a traditional Chinese herb derivative, achieved by targeting critical oncogenic mutations and enhancing cell death. Finally, we validate our theoretical results using wet lab experiments on HT29 and HCT116 human colorectal carcinoma cell lines.

Secretomes of Primary Cancer-associated Fibroblasts Upregulate the Expression of Stemness Markers in HT-29 Human Colorectal Carcinoma Cells

BACKGROUND: Cancer-associated fibroblast (CAF) is the most abundant tumor stroma. Our previous study has demonstrated that the secretomes of CAF isolated from colorectal carcinoma (CRC) patients could induce epithelial-mesenchymal transition in the HT-29 CRC cell line. However, the role of CAF secretomes in CRC stemness is needed to be further investigated. Therefore, the present study aimed to investigate the effect of CAF secretomes from CRC patients on the expression of stemness markers in HT-29 CRC cells in comparison with the secretomes from normal fibroblasts.METHODS: Fibroblasts were isolated from tumor (CAF) and their counterpart non-tumor (NF) areas of three CRC patients undergone surgical resection. Normal preputium fibroblasts (PF) were isolated during circumcision of three healthy boys aged 8 years. All fibroblasts were grown in free-serum culture medium for 24 hours to collect 50% (v/v) conditioned medium (CM). Then, CM was supplemented to HT-29 CRC cells for 72 hours. The effects of CAF- and NF-CM on the mRNA expression of CD44, CD133, OCT4, and ALDH1A1 were analysed using qRT-PCR. Cells proliferation was measured using the trypan blue exclusion assay.RESULTS: Supplementation of CAF-CM (50% v/v) significantly increased CD44, CD133, OCT4, and ALDH1A1 mRNA expressions compared to that of NF-CM and control without supplementation but had no effect on the proliferation of HT-29 cells.CONCLUSION: CAF secretomes from CRC patients upregulate the expression of CRC stemness.KEYWORDS: cancer-associated fibroblasts, ALDH1A1, OCT4, CD44, CD133, colorectal carcinoma

High Concentrations of Aspartame Induce Pro-Angiogenic Effects in Ovo and Cytotoxic Effects in HT-29 Human Colorectal Carcinoma Cells.

Aspartame (ASP), an artificial sweetener abundantly consumed in recent years in an array of dietary products, has raised some concerns in terms of toxicity, and it was even suggested a link with the risk of carcinogenesis (colorectal cancer), though the present scientific data are rather inconclusive. This study aims at investigating the potential role of aspartame in colorectal cancer by suggesting two experimental approaches: (i) an in vitro cytotoxicity screening in HT-29 human colorectal carcinoma cells based on cell viability (Alamar blue assay), cell morphology and cell migration (scratch assay) assessment and (ii) an in ovo evaluation in terms of angiogenic and irritant potential by means of the chorioallantoic membrane method (CAM). The in vitro results showed a dose-dependent cytotoxic effect, with a significant decrease of viable cells at the highest concentrations tested (15, 30 and 50 mM) and morphological cellular changes. In ovo, aspartame (15 and 30 mM) proved to have a pro-angiogenic effect and a weak irritant potential at the vascular level. These data suggest new directions of research regarding aspartame’s role in colorectal cancer.

Synthesis and characterization of proanthocyanidin-chitosan nanoparticles: An assessment on human colorectal carcinoma HT-29 cells

Cancer nanotheranostic materials are helpful in monitoring drug delivery and efficacy against tumor cells. Current chemotherapeutic may have adverse side effects and this necessity to discover the new modern therapeutic nano-drugs. In the present study, we designed the new targeted and degradable polymer of bio-active chitosan nanoparticles with proanthocyanidin (PAC-CSNPs) and evaluated its apoptotic effects against human colorectal carcinoma cells (HT-29). The functional groups were characterized by Fourier-transform infrared spectroscopy and transmission electron microscope. Further, their dispersion of spherical form nanoparticle with an average size of 73.43 nm used for drug delivery system. The PAC-CSNPs were targeted to inhibit the cyclin-dependent kinases and prevent cell cycle/cell division in cancer cells. At high concentrations of PAC (25 μg/mL) exposure, cell viability of HT-29 cells was greater than 80%. However, at low concentrations of PAC-CSNPs (6.25 μg/mL) exposure, HT-29 cell mortality was high, which may be due to the efficient drug release by CSNPs. The percentage of reactive oxygen species (ROS) levels were 12 ± 2.52% (control), 39 ± 4.32% (PAC), and 85.06 ± 3.54% (PAC-CSNPs). The over production of ROS by PAC-CSNPs can prompt DNA damage, cell death and apoptosis in HT-29 cells. The in vivo toxicity of synthesized PAC-CSNPs was tested against zebra fish observed at dose-time-dependent intervals. In conclusion, the PAC-CSNPs enhanced HT-29 cell death and shows promise as a novel future nano-therapy for cancer.

Hemocyanins from Helix and Rapana Snails Exhibit in Vitro Antitumor Effects in Human Colorectal Adenocarcinoma.

Hemocyanins are oxygen-transporting glycoproteins in the hemolymph of arthropods and mollusks that attract scientific interest with their diverse biological activities and potential applications in pharmacy and medicine. The aim of the present study was to assess the in vitro antitumor activity of hemocyanins isolated from marine snail Rapana venosa (RvH) and garden snails Helix lucorum (HlH) and Helix aspersa (HaH), as well the mucus of H. aspersa snails, in the HT-29 human colorectal carcinoma cell line. The effects of the hemocyanins on the cell viability and proliferation were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the alterations in the tumor cell morphology were examined by fluorescent and transmission electron microscopy. The results of the MTT assay showed that the mucus and α-subunit of hemocyanin from the snail H. aspersa had the most significant antiproliferative activity of the tested samples. Cytomorphological analysis revealed that the observed antitumor effects were associated with induction of apoptosis in the tumor cells. The presented data indicate that hemocyanins and mucus from H. aspersa have an antineoplastic activity and potential for development of novel therapeutics for treatment of colorectal carcinoma.

Orientin Induces G0/G1 Cell Cycle Arrest and Mitochondria Mediated Intrinsic Apoptosis in Human Colorectal Carcinoma HT29 Cells.

Colorectal carcinoma is one of the utmost diagnosed cancer with a steep increase in mortality rate. The incidence has been increasing in developing countries like India due to a westernization life style. Flavonoids have been explored widely for its various pharmacological activity including antitumor activity. Orientin, an analogue of luteolin (citrus flavonoid) isolated from rooibos and tulsi leaves is also expected to deliver significant antitumor activity similar to that of luteolin. The present study anticipates exploring the antitumor activity of orientin against colorectal carcinoma cells (HT29). Orientin exhibited remarkable cytotoxicity and antiproliferative activity against HT29 cells, which is clearly evident from tetrazolium based cytotoxicity and lactate dehydrogenase release assays. Orientin induce G0/G1 cell cycle arrest and regulates cyclin and cyclin-dependent protein kinases in order to prevent the entry of the cell cycle to the S phase. Annexin V-FITC (V-Fluorescein Isothiocyanate) dual staining reveals the apoptotic induction ability of orientin. The Bcl-2 family proteins along with the inhibitor of apoptotic proteins were regulated and the tumor suppressor p-53 expression have been decreased. In conclusion, our results proposed that orientin could be a potent chemotherapeutic agent against colorectal cancer after ascertaining their molecular mechanisms.

A molecular basis for the synergy between 17‑allylamino‑17‑demethoxy geldanamycin with Capecitabine and Irinotecan in human colorectal cancer cells through VEFG and MMP-9 gene expression

Anti-proliferative, anti-metastatic and anti-angiogenic effects of 17‑allylamino‑17‑demethoxy geldanamycin (17-AAG) were studied alone and in combination with Capecitabine (Cap) and/or Irinotecan (IR) on HT-29 human colorectal carcinoma cells. Expression of MMP-9 (matrix metalloproteinase‑9) and VEGF (vascular endothelial growth factor) mRNA was analyzed by real-time PCR method. The study was further followed by wound scratch assay for migration assessment. Nitric oxide content, Malondialdehyde generation and total anti-oxidant capacity were also assessed. Results showed significant differences between mono- and double therapy (p < 0.05). Combination of 17-AAG with IR or Cap resulted in synergistic effect (Combination Index < 1). Among double combination groups only Cap/17-AAG showed significant differences in MMP-9 and VEGF genes expression and wound healing assay. Moreover, a significant decrease of wound area in our triple combination group was obtained, indicating the antagonistic effect. IR/17-AAG and IR/Cap double combination groups resulted in down-regulation of MMP-9 and VEGF mRNA expression, respectively. Significant generation of MDA and decrease in TAC values have been observed in all our tested groups, however, the IR/17-AAG combination was the only group that could elevate NO concentration, significantly. Our findings demonstrated potent anti-angiogenesis and anti-metastatic effects for 17-AAG when it is provided in double combination especially with Cap, suggesting a new protocol in colorectal cancer combination therapy. These findings may indicate that down-regulation of VEGF and MMP-9 genes is directly related to angiogenesis and metastasis.

Structure and in vitro anticancer activity of sulfated O-polysaccharide from marine bacterium Poseidonocella pacifica KMM 9010T

We presented the structure of the sulfated polysaccharide moiety and anticancer activity in vitro of the О-deacylated lipopolysaccharide (DPS) isolated from the marine bacterium Poseidonocella pacifica KMM 9010T. The structure of O-polysaccharide was investigated by chemical methods along with 1H and 13C NMR spectroscopy. The O-polysaccharide was built up of sulfated disaccharide repeating units consisted of d-rhamnose (d-Rhaр) and 3-deoxy-d-manno-oct-2-ulosonic acid (Kdop): →7)-β-Kdoр4Ac5S-(2→3)-β-d-Rhaр2S-(1→. We demonstrated that the DPS from P. pacifica KMM 9010T non-toxic for normal mouse epidermal cells (JB6 Cl41 cell line) and inhibited colony formation of human colorectal carcinoma HT-29, breast adenocarcinoma MCF-7 and melanoma SK-MEL-5 cells in a dose-dependent manner.

Drotaverine - a Concealed Cytostatic!

Drotaverine (also known as dihydroperparine or No-Spa® ) is an antispasmodic drug closely related to papaverin. Drotaverin also acts as a cytostatic compound for several human tumor cell lines and nonmalignant mouse fibroblasts, and EC50 values as low as 3.0 μM were observed in SRB assays for HT-29 human colorectal carcinoma cells. Small structural changes (e.g., aromatization, benzylic oxidation) led to a reduced activity or a complete loss of cytotoxicity. Staining of the cells with acridine orange showed the cell membrane of the dead cells to be still intact, and a slight G1/G0 arrest in the treated cells was observed after 24 h. Extra annexin V-FITC/PI assays and flow cytometry revealed drotaverine mainly to act as a cytostatic and only to a minor extent as cytotoxic agent.

Extracellular Matrix-dependent Pathways in Colorectal Cancer Cell Lines Reveal Potential Targets for Anticancer Therapies.

Cancer cells grown in a 3D culture are more resistant to anticancer therapy treatment compared to those in a monolayer 2D culture. Emerging evidence has suggested that the key reasons for increased cell survival could be gene expression changes in cell-extracellular matrix (ECM) interaction-dependent manner. Global gene-expression changes were obtained in human colorectal carcinoma HT29 and DLD1 cell lines between 2D and laminin-rich (lr) ECM 3D growth conditions by gene-expression microarray analysis. The most significantly altered functional categories were revealed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The microarray data revealed that 841 and 1190 genes were differentially expressed in colorectal carcinoma DLD1 and HT29 cells. KEGG analysis indicated that the most significantly altered categories were cell adhesion, mitogen-activated protein kinase and immune response. Our results indicate altered pathways related to cancer development and progression and suggest potential ECM-regulated targets for the development of anticancer therapies.

Co-Culture of Tumor Spheroids and Fibroblasts in a Collagen Matrix-Incorporated Microfluidic Chip Mimics Reciprocal Activation in Solid Tumor Microenvironment.

Multicellular 3D culture and interaction with stromal components are considered essential elements in establishing a ‘more clinically relevant’ tumor model. Matrix-embedded 3D cultures using a microfluidic chip platform can recapitulate the microscale interaction within tumor microenvironments. As a major component of tumor microenvironment, cancer-associated fibroblasts (CAFs) play a role in cancer progression and drug resistance. Here, we present a microfluidic chip-based tumor tissue culture model that integrates 3D tumor spheroids (TSs) with CAF in proximity within a hydrogel scaffold. HT-29 human colorectal carcinoma cells grew into 3D TSs and the growth was stimulated when co-cultured with fibroblasts as shown by 1.5-folds increase of % changes in diameter over 5 days. TS cultured for 6 days showed a reduced expression of Ki-67 along with increased expression of fibronectin when co-cultured with fibroblasts compared to mono-cultured TSs. Fibroblasts were activated under co-culture conditions, as demonstrated by increases in α-SMA expression and migratory activity. When exposed to paclitaxel, a survival advantage was observed in TSs co-cultured with activated fibroblasts. Overall, we demonstrated the reciprocal interaction between TSs and fibroblasts in our 7-channel microfluidic chip. The co-culture of 3D TS-CAF in a collagen matrix-incorporated microfluidic chip may be useful to study the tumor microenvironment and for evaluation of drug screening and evaluation.

Comprehensive and Holistic Analysis of HT-29 Colorectal Cancer Cells and Tumor-Bearing Nude Mouse Model: Interactions Among Fractions Derived From the Chinese Medicine Formula Tian Xian Liquid in Effects on Human Colorectal Carcinoma.

The Chinese medicine formula Tian Xian Liquid (TXL) has been used clinically for cancer therapy in China for more than 25 years. However, the comprehensive and holistic effects of its bioactive fractions for various antitumor therapeutic effects have not been unraveled. This is the first study to scientifically elucidate the holistic effect of Chinese medicine formula for treating colon cancer, hence allowing a better understanding of the essence of Chinese medicine formula, through the comparison of the actions of TXL and its functional constituent fractions, including ethyl acetate (EA), butanol (BU), and aqueous (WA) fractions. Tissue-specific proliferative/antiproliferative effects of these fractions on human colorectal carcinoma HT-29 cells and splenocytes were studied by using the MTT assay. Their modulations on the expression of markers of antiproliferation, antimetastasis, reversion of multidrug resistance in treated HT-29 cells were examined with real-time polymerase chain reaction and Western blot analysis, and their modulations in a xenografted nude mouse model were examined by Western blot analysis. Results revealed that EA fraction slightly inhibited the proliferation of HT-29 cells, but tissue-specifically exerted the most potent antiproliferative effect on splenocytes. On the contrary, only TXL and BU fraction tissue-specifically contributed to the proliferation of splenocytes, but inhibited the proliferation of HT-29 cells. WA fraction exerted the most potent antiproliferative effect on HT-29 cells and also the strongest inhibitory action on tumor size in the nude mouse model in our previous study. In the HT-29 model, TXL and WA fraction exerted the most pronounced effect on upregulation of p21 mRNA and protein; TXL, and EA and WA fractions exerted the effect on downregulation of G1 phase cell cycle protein, cyclin D1 mRNA and protein; EA and BU fractions exerted the most prominent anti-invasive effect on anti-invasion via downregulation of MMP-1 mRNA; TXL potently reversed most multidrug resistance via downregulation of MDR-1 protein. In conclusion, the comprehensive and holistic effects of TXL were demonstrated with (a) mutual accentuation and mutual enhancement, (b) mutual counteraction and mutual suppression, and (c) mutual antagonism among the 3 constituent fractions. Moreover, the design of the present study may lead to further development of more tissue-specific effective drugs with minimal side effects for clinical use in combating carcinoma.

PH- and Thiol-Responsive BODIPY-Based Photosensitizers for Targeted Photodynamic Therapy.

A diiodo distyryl boron dipyrromethene (BODIPY) core was conjugated to two ferrocenyl quenchers through acid-labile ketal and/or thiol-cleavable disulfide linkers, of which the fluorescence and photosensitizing properties were significantly quenched through a photoinduced electron-transfer process. The two symmetrical analogues that contained either the ketal or disulfide linkers could only be activated by a single stimulus, whereas the unsymmetrical analogue was responsive to dual stimuli. Upon interaction with acid and/or dithiothreitol (DTT), these linkers were cleaved selectively. The separation of the BODIPY core and the ferrocenyl moieties restored the photoactivities of the former in phosphate buffered saline and inside the MCF-7 breast cancer cells, rendering these compounds as potential activable photosensitizers for targeted photodynamic therapy. The dual activable analogue exhibited the greatest enhancement in intracellular fluorescence intensity in both an acidic environment (pH 5) and the presence of DTT (4 mm). Its photocytotoxicity against MCF-7 cells also increased by about twofold upon preincubation with 4 mm of DTT. The activation of this compound was also demonstrated in nude mice bearing a HT29 human colorectal carcinoma. A significant increase in fluorescence intensity in the tumor was observed over 9 h after intratumoral injection.

Longitudinal tumor hypoxia imaging with [18F]FAZA-PET provides early prediction of nanoliposomal irinotecan (nal-IRI) treatment activity

BackgroundNon-invasive measurement of tumor hypoxia has demonstrated potential for the evaluation of disease progression, as well as prediction and assessment of treatment outcome. [18F]fluoroazomycin arabinoside (FAZA) positron emission tomography (PET) has been identified as a robust method for quantification of hypoxia both preclinically and clinically. The goal of this investigation was to evaluate the feasibility and value of repeated FAZA-PET imaging to quantify hypoxia in tumors that received multi-dose chemotherapy.MethodsFAZA-PET imaging was conducted over a 21-day period in a mouse xenograft model of HT-29 human colorectal carcinoma, following multi-dose chemotherapy treatment with irinotecan (CPT-11) or nanoliposomal irinotecan (nal-IRI, MM-398).ResultsTumors treated with 10 mg/kg nal-IRI maintained significantly lower levels of hypoxia and smaller hypoxic fractions compared to tumors that received 50 mg/kg CPT-11. Specifically, differences in FAZA uptake were detectable 9 days before any significant differences in tumor volume were observed between the treatment groups.ConclusionsThese findings highlight the potential use of FAZA-PET as an early marker of treatment response following multi-dose chemotherapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s13550-015-0135-x) contains supplementary material, which is available to authorized users.

Metabolism and antiproliferative effects of sulforaphane and broccoli sprouts in human intestinal (Caco-2) and hepatic (HepG2) cells

The purpose of this work was to study the absorption and metabolism of sulforaphane (SFN) from broccoli sprouts, their major glucosinolate glucoraphanin and its hydrolysis product SFN. This was done by monitoring SFN's main metabolites, i.e. SFN, SFN-glutathione and SFN-cysteine, in two different cell models of absorption and metabolism (Caco-2 colorectal carcinoma cells and HepG2 hep- atocellular carcinoma cells), during 3, 6, and 24 h of treatment, using a selective UHPLC-QqQ-MS/MS procedure. Concentrations ranging 0.5-90 nmol/l were found within the cells and released in the medium, depending on the type of analyte under study. Cells were capable of conjugative metabolism, since the SFN mercapturic derivatives could be identified in the cell medium. The antiproliferative activity of broccoli sprouts, glucoraphanin and sul- foraphane was compared in Caco-2 and HT-29 human colorectal carcinoma cells, and HepG2 hepatocellular carcinoma cells, establishing the minimal concentration of a given compound to achieve half inhibition of the maximal cell growth (IC50) for broccoli sprouts extract and sulforaphane. However, glucoraphanin did not show an antiproliferative effect in the cells under study.