Phospholipid profiling enables to discriminate tumor- and non-tumor-derived human colon epithelial cells: Phospholipidome similarities and differences in colon cancer cell lines and in patient-derived cell samples.

Identification of changes of phospholipid (PL) composition occurring during colorectal cancer (CRC) development may help us to better understand their roles in CRC cells. Here, we used LC-MS/MS-based PL profiling of cell lines derived from normal colon mucosa, or isolated at distinct stages of CRC development, in order to study alterations of PL species potentially linked with cell transformation. We found that a detailed evaluation of phosphatidylinositol (PI) and phosphatidylserine (PS) classes allowed us to cluster the studied epithelial cell lines according to their origin: i) cells originally derived from normal colon tissue (NCM460, FHC); ii) cell lines derived from colon adenoma or less advanced differentiating adenocarcinoma cells (AA/C1, HT-29); or, iii) cells obtained by in vitro transformation of adenoma cells and advanced colon adenocarcinoma cells (HCT-116, AA/C1/SB10, SW480, SW620).

Activation of autophagy and PPARγ protect colon cancer cells against apoptosis induced by interactive effects of butyrate and DHA in a cell type-dependent manner: The role of cell differentiation.

The short-chain and n-3 polyunsaturated fatty acids exhibit anticancer properties, and they may mutually interact within the colon. However, the molecular mechanisms of their action in colon cancer cells are still not fully understood. Our study focused on the mechanisms responsible for the diverse effects of sodium butyrate (NaBt), in particular when interacting with docosahexaenoic acid (DHA), in distinct colon cancer cell types, in which NaBt either induces cell differentiation or activates programmed cell death involving mitochondrial pathway.

Aberrant DR5 transport through disruption of lysosomal function suggests a novel mechanism for receptor activation.

To examine reciprocal or unilateral implications between two cell destruction processes, autophagy and apoptosis, in 5-Fluorouracil (5-FU)-treated tumor cells, a combination of chemical inhibitors, RNAi and genetic approaches were used. In contrast to cancer cells harboring obstructed apoptosis, either at the DISC or the mitochondrial level, p53-deficiency generated signs of autophagy deregulation upon chemotherapy. On the other, hand disruption of lysosomal function by chloroquine, caused a profound decrease in apoptotic markers appearing in response to 5-FU.

Dietary fatty acids specifically modulate phospholipid pattern in colon cells with distinct differentiation capacities.

Purpose: Although beneficial effects of the dietary n-3 docosahexaenoic acid (DHA) or butyrate in colon carcinogenesis have been implicated, the mechanisms of their action are not fully clear. Here, we investigated modulations of composition of individual phospholipid (PL) classes, with a particular emphasis on cardiolipins (CLs), in colon cells treated with DHA, sodium butyrate (NaBt), or their combination (DHA/NaBt), and we evaluated possible associations between lipid changes and cell fate after fatty acid treatment.

Methods: In two distinct human colon cell models, foetal colon (FHC) and adenocarcinoma (HCT-116) cells, we compared patterns and composition of individual PL classes following the fatty acid treatment by HPLC-MS/MS.

5-Fluorouracil-induced RNA stress engages a TRAIL-DISC-dependent apoptosis axis facilitated by p53.

Despite recent advances in targeted therapeutics, administration of 5-fluorouracil (5-FU) remains a common clinical strategy for post-surgical treatment of solid tumors. Although it has been proposed that RNA metabolism is disturbed by 5-FU treatment, the key cytotoxic response is believed to be enzymatic inhibition of thymidylate synthase resulting in nucleotide pool disproportions. An operating p53 tumor suppressor signaling network is in many cases essential for the efficiency of chemotherapy, and malfunctions within this system remain a clinical obstacle.

Interaction of dietary fatty acids with tumour necrosis factor family cytokines during colon inflammation and cancer.

Intestinal homeostasis is precisely regulated by a number of endogenous regulatory molecules but significantly influenced by dietary compounds. Malfunction of this system may result in chronic inflammation and cancer. Dietary essential n-3 polyunsaturated fatty acids (PUFAs) and short-chain fatty acid butyrate produced from fibre display anti-inflammatory and anticancer activities.

Docosahexaenoic fatty acid (DHA) in the regulation of colon cell growth and cell death: a review.

Background: Experimental, epidemiological and clinical data substantiate the beneficial role of n-3 polyunsaturated fatty acids (PUFAs) in preventing inflammation and cancer of the colon. This review covers the unsaturated docosahexaenoic fatty acid (DHA), describes some of its important cellular and molecular mechanisms, its interaction with another dietary lipid, butyrate and with endogenous apoptotic regulators of the tumour necrosis factor (TNF) family. We also discuss the clinical impact of this knowledge and the use of these lipids in colon cancer prevention and treatment.

Necroptosis modulated by autophagy is a predominant form of melanoma cell death induced by sanguilutine.

We show that the plant quaternary benzo[c]phenanthridine alkaloid sanguilutine (SL) is a strong inducer of caspase-independent non-apoptotic death in human melanoma cells. Necrostatin-1, a specific inhibitor of necroptosis, completely reversed the cytotoxic effect of SL, suggesting that necroptosis was a predominant type of cell death induced by SL in these cells. In addition, we showed that SL can trigger an autophagic response, as confirmed by GFP-LC3 puncta formation and LC3-II accumulation.

miRNA-214 modulates radiotherapy response of non-small cell lung cancer cells through regulation of p38MAPK, apoptosis and senescence.

Background: Radio- and chemotherapy (RT/CT) resistance hampers success in combating small and non-small cell lung cancers (SCLC/NSCLC). The underlying molecular mechanisms of RT/CT resistance of LCs are multifactorial and have been understood in part hitherto. miRNAs, key regulators of mRNAs, are well-recognised oncomirs; however, their role in regulating RT response remains poorly understood.

Lipid alterations in human colon epithelial cells induced to differentiation and/or apoptosis by butyrate and polyunsaturated fatty acids.

The present study highlights the important association between lipid alterations and differentiation/apoptotic responses in human colon differentiating (FHC) and nondifferentiating (HCT-116) cell lines after their treatment with short-chain fatty acid sodium butyrate (NaBt), polyunsaturated fatty acids (PUFAs), and/or their combination. Our data from GC/MS and LC/MS/MS showed an effective incorporation and metabolization of the supplemented arachidonic acid (AA) or docosahexaenoic acid (DHA), resulting in an enhanced content of the respective PUFA in individual phospholipid (PL) classes and an altered composition of the whole cellular fatty acid spectrum in both FHC and HCT-116 cells. We provide novel evidence that NaBt combined with PUFAs additionally modulated AA and DHA cellular levels and caused their shift from triacylglycerol to PL fractions.

Combined inhibition of DNA methyltransferase and histone deacetylase restores caspase-8 expression and sensitizes SCLC cells to TRAIL.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising drug for the treatment of tumors; however, a number of cancer cells are resistant to this cytokine. Among the mechanisms of resistance of small cell lung carcinomas (SCLCs) to TRAIL is the lack of caspase-8 expression. Although methylation of the caspase-8 promoter has been suggested as the main mechanism of caspase-8 silencing, we showed that reduction of the enzymes involved in DNA methylation, DNA methyltransferases (DNMT) 1, 3a and 3b, was not sufficient to significantly restore caspase-8 expression in SCLC cells, signifying that other mechanisms are involved in caspase-8 silencing.

Detachment-mediated resistance to TRAIL-induced apoptosis is associated with stimulation of the PI3K/Akt pathway in fetal and adenocarcinoma epithelial colon cells.

The resistance of transformed epithelial cells to a detachment-induced apoptosis (anoikis) can significantly affect their susceptibility to anticancer therapy. We showed that detachment of both fetal (FHC) and adenocarcinoma (HT-29) human colon epithelial cells resulted in the activation of the pro-survival Akt pathway, and significant changes in integrin-linked kinase (ILK) and focal adhesive kinase (FAK) phosphorylation. We demonstrated a detachment-induced and PI3K/Akt-mediated resistance to apoptotic effects of TRAIL, which was not associated with any changes in the cell surface TRAIL death receptor levels.

Lower sensitivity of FHC fetal colon epithelial cells to photodynamic therapy compared to HT-29 colon adenocarcinoma cells despite higher intracellular accumulation of hypericin.

Preferential uptake of photosensitizer by tumour tissue is an elementary prerequisite of effective and successful photodynamic therapy (PDT). Therefore intracellular concentration of photosensitizer is one of the limiting factors affecting PDT efficiency. Hypericin (HY) has found applications in photodynamic diagnostics solely due to its high specificity for tumour cells and tissues.

Cisplatin and a potent platinum(IV) complex-mediated enhancement of TRAIL-induced cancer cells killing is associated with modulation of upstream events in the extrinsic apoptotic pathway.

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) can selectively trigger apoptosis in various cancer cell types. However, many cancer cells are resistant to death receptor-mediated apoptosis. Combination therapy with platinum complexes may affect TRAIL-induced signaling via modulation of various steps in apoptotic pathways.

LA-12 overcomes confluence-dependent resistance of HT-29 colon cancer cells to Pt (II) compounds.

Background: LA-12 is a new platinum (IV) drug with promising cytotoxic effects in a wide range of cancer cell lines. Its confluence-dependent effects were compared with cisplatin (CDDP) and oxaliplatin (L-OHP) in HT-29 cells.

Materials And Methods: Cytotoxicity was determined by MTT test, eosin exclusion assay, and cell number quantification.

Doxorubicin and etoposide sensitize small cell lung carcinoma cells expressing caspase-8 to TRAIL.

Background: TRAIL is considered as a promising anti-cancer agent, because of its ability to induce apoptosis in cancer but not in most normal cells. However, growing evidence exist that many cancer cells are resistant to its apoptotic effects. SCLC is a typical example of tumor entity where TRAIL monotherapy is not efficient.

Tudor staphylococcal nuclease is an evolutionarily conserved component of the programmed cell death degradome.

Programmed cell death (PCD) is executed by proteases, which cleave diverse proteins thus modulating their biochemical and cellular functions. Proteases of the caspase family and hundreds of caspase substrates constitute a major part of the PCD degradome in animals. Plants lack close homologues of caspases, but instead possess an ancestral family of cysteine proteases, metacaspases.

Differences in TRAIL-induced changes of Mcl-1 expression among distinct human colon epithelial cell lines.

In addition to its ability to act as a promising inducer of tumor-specific cell death, TRAIL has also been shown to stimulate signaling pathways leading to cancer cell survival. We examined the changes of anti-apoptotic Mcl-1 protein level following TRAIL treatment of human cell lines representing different stages of colon carcinogenesis-adenocarcinoma (HT-29, HCT116) or secondary metastasis (SW620), together with cell line derived from human fetal colon (FHC). While TRAIL was capable of triggering an anti-apoptotic signaling leading to significant early ERK-mediated transcriptional up-regulation of Mcl-1 in selected colon adenocarcinoma cell lines, none or very limited effects were demonstrated in cell lines derived from colon lymph node metastasis or fetal colon, respectively.

Human fetal colon cells and colon cancer cells respond differently to butyrate and PUFAs.

We verified the hypothesis suggesting modulation of the effects of sodium butyrate (NaBt) by omega-3 or omega-6 PUFAs. Comparing the response of human colon epithelial cell lines of fetal (FHC) and adenocarcinoma (HT-29, HCT-116) origin, we detected significant differences in proliferation, differentiation and apoptotic response to the treatment of NaBt, arachidonic or docosahexaenoic acids and their combination. While in FHC and HT-29 cells NaBt induced G0/G1 arrest, differentiation and low level of apoptosis, in HCT-116 cells G2/M arrest, no differentiation and high degree of apoptosis were detected.

The interaction of butyrate with TNF-alpha during differentiation and apoptosis of colon epithelial cells: role of NF-kappaB activation.

We demonstrated that TNF-alpha suppressed differentiation and potentiated cell death induced by butyrate (NaBt) in both adenocarcinoma HT-29 and fetal FHC human colon cells in vitro. Since TNF-alpha is a typical activator of NF-kappaB pathway, we studied the role of NF-kappaB activation in cell differentiation and death during the TNF-alpha and NaBt co-treatment. TNF-alpha induced rapid NF-kappaB activation in both HT-29 and FHC cell lines and this effect was differently modulated by NaBt in these two cell lines.

Caspases: determination of their activities in apoptotic cells.

Caspases, a family of cysteine proteases, were identified as major regulators of apoptotic cell death. These enzymes are involved not only in initiation but also in an execution phase of apoptosis by cleaving more than 400 substrates. This cleavage mediates a majority of the typical biochemical and morphological changes in apoptotic cells, such as cell shrinkage, chromatin condensation, DNA fragmentation, and plasma membrane blebbing.

Novel Anticancer Platinum(IV) Complexes with Adamantylamine: Their Efficiency and Innovative Chemotherapy Strategies Modifying Lipid Metabolism.

The impressive impact of cisplatin on cancer on one side and severe side effects, as well as the development of drug resistance during treatment on the other side, were the factors motivating scientists to design and synthesize new more potent analogues lacking disadvantages of cisplatin. Platinum(IV) complexes represent one of the perspective groups of platinum-based drugs. In this review, we summarize recent findings on both in vitro and in vivo effects of platinum(IV) complexes with adamantylamine.

Response of normal and colon cancer epithelial cells to TNF-family apoptotic inducers.

We compared the response of normal (FHC) and cancer (HT-29) human colon epithelial cells to the important apoptotic inducers TNF-alpha, anti-Fas antibody and TNF-related apoptosis inducing ligand (TRAIL). The two cell lines did not respond to TNF-alpha (15 ng/ml), expressed a limited sensitivity to anti-Fas antibody (200 ng/ml) and a different response to TRAIL (100 ng/ml). We studied apoptosis with regard to the changes at the receptor level (DR, DcR and FLIP) and at the level of mitochondria (Bid protein cleavage, Apo2.

Necrosis predominates in the cell death of human colon adenocarcinoma HT-29 cells treated under variable conditions of photodynamic therapy with hypericin.

Photodynamic therapy (PDT) represents a new rapidly-developing anticancer approach based on administration of a non- or weakly-toxic photosensitizer and its activation with light of appropriate wavelength. Hypericin, one of the promising photosensitizers, is known to induce apoptosis with high efficiency in various cell line models. However, here we report the prevalence of necrosis accompanied by suppression of caspase-3 activation in colon adenocarcinoma HT-29 cells exposed to an extensive range of PDT doses evoked by variations in two variables -- hypericin concentration and light dose.