Oxysterols play significant roles in many physiological and pathological processes including cancer. They modulate some of the cancer hallmarks pathways, influence the efficacy of anti-cancer drugs, and associate with patient survival. In this study, we aimed to analyze the role of 7-ketocholesterol (7-KC) in breast carcinoma cells and its potential modulation of the tamoxifen effect. 7-KC effects were studied in two estrogen receptor (ER)-positive (MCF-7 and T47D) and one ER-negative (BT-20) breast cancer cell lines. First, we tested the viability of cells in the presence of 7-KC. Next, we co-incubated cells with tamoxifen and sublethal concentrations of 7-KC. We also tested changes in caspase 3/7 activity, deregulation of the cell cycle, and changes in expression of selected genes/proteins in the presence of tamoxifen, 7-KC, or their combination. Finally, we analyzed the effect of 7-KC on cellular migration and invasion. We found that the presence of 7-KC slightly decreases the efficacy of tamoxifen in MCF-7 cells, while an increased effect of tamoxifen and higher caspase 3/7 activity was observed in the BT-20 cell line. In the T47D cell line, we did not find any modulation of tamoxifen efficacy by the presence of 7-KC. Expression analysis showed the deregulation in CYP1A1 and CYP1B1 with the opposite trend in MCF-7 and BT-20 cells. Moreover, 7-KC increased cellular migration and invasion potential regardless of the ER status. This study shows that 7-KC can modulate tamoxifen efficacy as well as cellular migration and invasion, making 7-KC a promising candidate for future studies.

• Keywords
• 7-ketocholesterol, Breast cancer, Migration, Proliferation, Tamoxifen,
• MeSH
• Drug Resistance, Neoplasm MeSH
• Antineoplastic Agents, Hormonal pharmacology   MeSH
• Caspase 3 genetics   MeSH
• Humans MeSH
• MCF-7 Cells MeSH
• Cell Line, Tumor MeSH
• Breast Neoplasms * drug therapy   MeSH
• Cell Proliferation MeSH
• Receptors, Estrogen metabolism   MeSH
• Tamoxifen * pharmacology   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 7-ketocholesterol MeSH Browser
• Antineoplastic Agents, Hormonal MeSH
• Caspase 3 MeSH
• Receptors, Estrogen MeSH
• Tamoxifen * MeSH

The main problem precluding successful therapy with conventional taxanes is de novo or acquired resistance to taxanes. Therefore, novel experimental taxane derivatives (Stony Brook taxanes; SB-Ts) are synthesized and tested as potential drugs against resistant solid tumors. Recently, we reported alterations in ABCC3, CPS1, and TRIP6 gene expression in a breast cancer cell line resistant to paclitaxel. The present study aimed to investigate gene expression changes of these three candidate molecules in the highly resistant ovarian carcinoma cells in vitro and corresponding in vivo models treated with paclitaxel and new experimental Stony Brook taxanes of the third generation (SB-T-121605 and SB-T-121606). We also addressed their prognostic meaning in ovarian carcinoma patients treated with taxanes. We estimated and observed changes in mRNA and protein profiles of ABCC3, CPS1, and TRIP6 in resistant and sensitive ovarian cancer cells and after the treatment of resistant ovarian cancer models with paclitaxel and Stony Brook taxanes in vitro and in vivo. Combining Stony Brook taxanes with paclitaxel caused downregulation of CPS1 in the paclitaxel-resistant mouse xenograft tumor model in vivo. Moreover, CPS1 overexpression seems to play a role of a prognostic biomarker of epithelial ovarian carcinoma patients' poor survival. ABCC3 was overexpressed in EOC tumors, but after the treatment with taxanes, its up-regulation disappeared. Based on our results, we can suggest ABCC3 and CPS1 for further investigations as potential therapeutic targets in human cancers.

• Keywords
• ABCC3, CPS1, Stony Brook taxanes, TRIP6, multidrug resistance, ovarian carcinoma, taxanes,
• MeSH
• Adaptor Proteins, Signal Transducing genetics   MeSH
• Drug Resistance, Neoplasm genetics   MeSH
• Down-Regulation drug effects   genetics   MeSH
• Carcinoma, Ovarian Epithelial drug therapy   genetics   MeSH
• Carbamoyl-Phosphate Synthase (Ammonia) genetics   MeSH
• Middle Aged MeSH
• Humans MeSH
• Mice, Nude MeSH
• Mice MeSH
• Biomarkers, Tumor genetics   MeSH
• Cell Line, Tumor MeSH
• Ovarian Neoplasms drug therapy   genetics   MeSH
• Paclitaxel therapeutic use   MeSH
• LIM Domain Proteins genetics   MeSH
• Multidrug Resistance-Associated Proteins genetics   MeSH
• Taxoids therapeutic use   MeSH
• Transcription Factors genetics   MeSH
• Cell Survival drug effects   genetics   MeSH
• Animals MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Adaptor Proteins, Signal Transducing MeSH
• CPS1 protein, human MeSH Browser
• Carbamoyl-Phosphate Synthase (Ammonia) MeSH
• multidrug resistance-associated protein 3 MeSH Browser
• Biomarkers, Tumor MeSH
• Paclitaxel MeSH
• LIM Domain Proteins MeSH
• Multidrug Resistance-Associated Proteins MeSH
• Taxoids MeSH
• Transcription Factors MeSH
• TRIP6 protein, human MeSH Browser

Colorectal cancer is one of the most common cancers and pancreatic cancer is among the most fatal and difficult to treat. New prognostic biomarkers are urgently needed to improve the treatment of colorectal and pancreatic cancer. Protein regulating cytokinesis 1 (PRC1), kinesin family member 14 (KIF14) and citron Rho-interacting serine/threonine kinase (CIT) serve important roles in cytokinesis, are strongly associated with cancer progression and have prognostic potential. The present study aimed to investigate the prognostic relevance of the PRC1, KIF14 and CIT genes in colorectal and pancreatic cancer. PRC1, KIF14 and CIT transcript expression was assessed by reverse transcription-quantitative PCR in tumors and paired distant unaffected mucosa from 67 patients with colorectal cancer and tumors and paired non-neoplastic control tissues from 48 patients with pancreatic cancer. The extent of transcript dysregulation between tumor and control tissues and between groups of patients divided by main clinical characteristics, namely patients' age and sex, disease stage, localization and grade, was determined. Finally, the associations of transcript levels in tumors with disease-free interval and overall survival time were evaluated. PRC1, KIF14 and CIT transcripts were upregulated in tumors compared with control tissues. PRC1, KIF14 and CIT levels strongly correlated to each other in both colorectal and pancreatic tumor and control tissues after correction for multiple testing. However, no significant associations were found among the transcript levels of PRC1, KIF14 and CIT and disease-free interval or overall survival time. In summary, the present study demonstrated mutual correlation of PRC1, KIF14 and CIT cytokinesis regulators with no clear prognostic value in pancreatic and colorectal cancers. Hence, according to the results of the present study, transcript levels of these genes cannot be clinically exploited as prognostic biomarkers in colorectal or pancreatic cancer patients.

• Keywords
• cancer, colon, cytokinesis, gene expression, pancreas, prognosis, rectum,
• Publication type
• Journal Article MeSH

The KRAS signalling pathway is pivotal for pancreatic ductal adenocarcinoma (PDAC) development. After the failure of most conventional cytotoxic and targeted therapeutics tested so far, the combination of taxane nab-paclitaxel (Abraxane) with gemcitabine recently demonstrated promising improvements in the survival of PDAC patients. This study aimed to explore interactions of conventional paclitaxel and experimental taxane SB-T-1216 with the KRAS signalling pathway expression in in vivo and in vitro PDAC models in order to decipher potential predictive biomarkers or targets for future individualised therapy. Mouse PDAC PaCa-44 xenograft model was used for evaluation of changes in transcript and protein levels of the KRAS signalling pathway caused by administration of experimental taxane SB-T-1216 in vivo. Subsequently, KRAS wild-type (BxPc-3) and mutated (MiaPaCa-2 and PaCa-44) cell line models were treated with paclitaxel to verify dysregulation of the KRAS signalling pathway gene expression profile in vitro and investigate the role of KRAS mutation status. By comparing the gene expression profiles, this study observed for the first time that in vitro cell models differ in the basal transcriptional profile of the KRAS signalling pathway, but there were no differences between KRAS mutated and wild-type cells in sensitivity to taxanes. Generally, the taxane administration caused a downregulation of the KRAS signalling pathway both in vitro and in vivo, but this effect was not dependent on the KRAS mutation status. In conclusion, putative biomarkers for prediction of taxane activity or targets for stimulation of taxane anticancer effects were not discovered by the KRAS signalling pathway profiling in various PDAC models.

• MeSH
• Albumins pharmacology   MeSH
• Deoxycytidine analogs & derivatives   pharmacology   MeSH
• Carcinoma, Pancreatic Ductal drug therapy   genetics   MeSH
• Gemcitabine MeSH
• Humans MeSH
• Mice, Nude MeSH
• Mice MeSH
• Biomarkers, Tumor genetics   MeSH
• Cell Line, Tumor MeSH
• Pancreatic Neoplasms drug therapy   genetics   MeSH
• Paclitaxel pharmacology   MeSH
• Bridged-Ring Compounds pharmacology   MeSH
• Cell Proliferation drug effects   genetics   MeSH
• Antineoplastic Combined Chemotherapy Protocols pharmacology   MeSH
• Proto-Oncogene Proteins p21(ras) genetics   MeSH
• Signal Transduction drug effects   genetics   MeSH
• Taxoids pharmacology   MeSH
• Transcriptome drug effects   genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 130-nm albumin-bound paclitaxel MeSH Browser
• Albumins MeSH
• Deoxycytidine MeSH
• Gemcitabine MeSH
• KRAS protein, human MeSH Browser
• Biomarkers, Tumor MeSH
• Paclitaxel MeSH
• Bridged-Ring Compounds MeSH
• Proto-Oncogene Proteins p21(ras) MeSH
• taxane MeSH Browser
• Taxoids MeSH

Silychristin A is the second most abundant compound of silymarin. Silymarin complex was previously described as an antioxidant with multidrug resistance modulation activity. Here, the results of a classical biochemical antioxidant assay (ORAC) were compared with a cellular assay evaluating the antioxidant capacity of pure silychristin A and its derivatives (anhydrosilychristin, isosilychristin and 2,3-dehydrosilychristin A). All the tested compounds acted as antioxidants within the cells, but 2,3-dehydro- and anhydro derivatives were almost twice as potent as the other tested compounds. Similar results were obtained in LPS-stimulated macrophages, where 2,3-dehydro- and anhydrosilychristin inhibited NO production nearly twice as efficiently as silychristin A. The inhibition of P-glycoprotein (P-gp) was determined in vitro, and the respective sensitization of doxorubicin-resistant ovarian carcinoma overproducing P-gp was detected. Despite the fact that the inhibition of P-gp was demonstrated in a concentration-dependent manner for each tested compound, the sensitization of the resistant cell line was observed predominantly for silychristin A and 2,3-dehydrosilychristin A. However, anhydrosilychristin and isosilychristin affected the expression of both the P-gp (ABCB1) and ABCG2 genes. This is the first report showing that silychristin A and its 2,3-dehydro-derivative modulate multidrug resistance by the direct inhibition of P-gp, in contrast to anhydrosilychristin and isosilychristin modulating multidrug resistance by downregulating the expression of the dominant transmembrane efflux pumps.

• Keywords
• ABC superfamily, Adriamycin, BCRP, P-glycoprotein, expression profile, immunomodulation, silychristin, silymarin,
• Publication type
• Journal Article MeSH

Dietary selenium (Se) intake is essential for synthesizing selenoproteins that are important in countering oxidative and inflammatory processes linked to colorectal carcinogenesis. However, there is limited knowledge on the selenoprotein expression in colorectal adenoma (CRA) and colorectal cancer (CRC) patients, or the interaction with Se status levels. We studied the expression of seventeen Se pathway genes (including fifteen of the twenty-five human selenoproteins) in RNA extracted from disease-normal colorectal tissue pairs, in the discovery phase of sixty-two CRA/CRC patients from Ireland and a validation cohort of a hundred and five CRC patients from the Czech Republic. Differences in transcript levels between the disease and paired control mucosa were assessed by the Mann-Whitney U-test. GPX2 and TXNRD3 showed a higher expression and GPX3, SELENOP, SELENOS, and SEPHS2 exhibited a lower expression in the disease tissue from adenomas and both cancer groups (p-values from 0.023 to <0.001). In the Czech cohort, up-regulation of GPX1, SELENOH, and SOD2 and down-regulation of SELENBP1, SELENON, and SELENOK (p-values 0.036 to <0.001) was also observed. We further examined the correlation of gene expression with serum Se status (assessed by Se and selenoprotein P, SELENOP) in the Irish patients. While there were no significant correlations with both Se status markers, SELENOF, SELENOK, and TXNRD1 tumor tissue expression positively correlated with Se, while TXNRD2 and TXNRD3 negatively correlated with SELENOP. In an analysis restricted to the larger Czech CRC patient cohort, Cox regression showed no major association of transcript levels with patient survival, except for an association of higher SELENOF gene expression with both a lower disease-free and overall survival. Several selenoproteins were differentially expressed in the disease tissue compared to the normal tissue of both CRA and CRC patients. Altered selenoprotein expression may serve as a marker of functional Se status and colorectal adenoma to cancer progression.

• Keywords
• biomarkers, cancer risk, colorectal adenoma, colorectal cancer, colorectal neoplasm, gene expression, selenium (Se), selenoproteins, selenium status, selenoprotein P,
• MeSH
• Adenoma blood   genetics   MeSH
• Genetic Markers MeSH
• Glutathione Peroxidase genetics   metabolism   MeSH
• Cohort Studies MeSH
• Colorectal Neoplasms blood   genetics   MeSH
• Middle Aged MeSH
• Humans MeSH
• Proportional Hazards Models MeSH
• Gene Expression Regulation MeSH
• Selenium blood   MeSH
• Selenoprotein P genetics   metabolism   MeSH
• Selenoproteins genetics   metabolism   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Thioredoxin-Disulfide Reductase genetics   metabolism   MeSH
• Thioredoxin Reductase 1 genetics   metabolism   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Ireland MeSH
• Names of Substances
• Genetic Markers MeSH
• Glutathione Peroxidase MeSH
• GPX2 protein, human MeSH Browser
• Selenium MeSH
• SELENOF protein, human MeSH Browser
• Selenoprotein P MeSH
• Selenoproteins MeSH
• Thioredoxin-Disulfide Reductase MeSH
• Thioredoxin Reductase 1 MeSH
• TXNRD1 protein, human MeSH Browser
• TXNRD3 protein, human MeSH Browser

Pancreatic ductal adenocarcinoma (PDAC) is a tumor with a poor prognosis, and no targeted therapy is currently available. The aim of the present study was to investigate the prognostic significance of the expression of V-Ki-ras2 Κirsten rat sarcoma viral oncogene homolog (KRAS), downstream signaling pathway genes and the association with clinical characteristics in PDAC patients undergoing radical surgery. Tumors and adjacent non-neoplastic pancreatic tissues were examined in 45 patients with histologically verified PDAC. KRAS and B-Raf proto-oncogene, serine/threonine kinase (BRAF) gene mutation analysis was performed using the KRAS/BRAF/phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α array. The transcript profile of 52 KRAS downstream signaling pathway genes was assessed using quantitative-polymerase chain reaction. KRAS mutation was detected in 80% of cases. The genes of four signaling pathways downstream of KRAS, including the phosphoinositide 3-kinase/3-phosphoinositide-dependent protein kinase 1/V-akt murine thymoma viral oncogene homolog 1, RAL guanine nucleotide exchange factor, Ras and Rab interactor 1/ABL proto-oncogene-1, non-receptor tyrosine kinase, and RAF proto-oncogene serine/threonine-protein kinase/mitogen-activated protein kinase pathways, exhibited differential expression in PDAC compared with that in the adjacent normal tissues. However, no significant differences in expression were evident between patients with KRAS-mutated and wild-type tumors. The expression of KRAS downstream signaling pathways genes did not correlate with angioinvasion, perineural invasion, grade or presence of lymph node metastasis. Additionally, the presence of KRAS mutations was not associated with overall survival. Among the KRAS downstream effective signaling pathways molecules investigated, only v-raf-1 murine leukemia viral oncogene homolog 1 expression was predictive of prognosis. Overall, KRAS mutation is present in the majority of cases of PDAC, but is not associated with changes in the expression of KRAS downstream signaling pathways and the clinical outcome. This may partly explain the failure of KRAS-targeted therapies in PDAC.

• Keywords
• KRAS, gene expression, mutation, overall survival, pancreatic ductal adenocarcinoma,
• Publication type
• Journal Article MeSH

Epithelial ovarian cancer (EOC) has the highest mortality among gynecological carcinomas. The lack of specific markers for prognostic determination of EOC progression hinders the search for novel effective therapies. The aim of the present study was (i) to explore differences in expressions of ATP-binding cassette (ABC) and solute carrier (SLC) transporter genes, genes associated with drug metabolism and cell cycle regulation between control ovarian tissues (n = 14), primary EOCs (n = 44) and intraperitoneal metastases (n = 29); (ii) to investigate associations of gene expression levels with prognosis of patients with intraperitoneal metastases. In all tissue samples, transcript levels of the above target genes were assessed using quantitative real-time PCR. Gene expression levels were compared between particular tissue types and evaluated with regard to progression-free survival (PFS) and drug-resistance status of patients with metastases. Gene expression of ABCA7 significantly increased and that of ESR2 decreased in the order control ovarian tissues - primary EOCs - metastases. High expressions of ABCA2/8/9/10, ABCB1, ABCC9, ABCG2, ATP7A, SLC16A14, and SOD3 genes were significantly associated with longer progression-free survival of patients. In intraperitoneal metastases, expression of all of these genes highly correlated and indicated prognostic profile. Transporters from the ABCA family, ABCG2, and ESR2 are involved mainly in lipid metabolism, membrane transport, and cell proliferation. These processes are thus probably the most important for EOC progression. Based on these results, we have proposed novel markers of ovarian carcinoma progression and metastatic spread which might be potentially useful as therapeutic targets. Their significance should be further explored on a larger independent set of patients.

• Keywords
• epithelial ovarian cancer, gene expression., markers, metastases, progression,
• Publication type
• Journal Article MeSH

The Hedgehog pathway is one of the major driver pathways in pancreatic ductal adenocarcinoma. This study investigated prognostic importance of Hedgehog signaling pathway in pancreatic cancer patients who underwent a radical resection. Tumors and adjacent non-neoplastic pancreatic tissues were obtained from 45 patients with histologically verified pancreatic cancer. The effect of experimental taxane chemotherapy on the expression of Hedgehog pathway was evaluated in vivo using a mouse xenograft model prepared using pancreatic cancer cell line Paca-44. Mice were treated by experimental Stony Brook Taxane SB-T-1216. The transcript profile of 34 Hedgehog pathway genes in patients and xenografts was assessed using quantitative PCR. The Hedgehog pathway was strongly overexpressed in pancreatic tumors and upregulation of SHH, IHH, HHAT and PTCH1 was associated with a trend toward decreased patient survival. No association of Hedgehog pathway expression with KRAS mutation status was found in tumors. Sonic hedgehog ligand was overexpressed, but all other downstream genes were downregulated by SB-T-1216 treatment in vivo. Suppression of HH pathway expression in vivo by taxane-based chemotherapy suggests a new mechanism of action for treatment of this aggressive tumor.

• MeSH
• Carcinoma, Pancreatic Ductal drug therapy   genetics   MeSH
• Middle Aged MeSH
• Humans MeSH
• Mutation MeSH
• Mice, Nude MeSH
• Pancreatic Neoplasms drug therapy   genetics   MeSH
• Disease-Free Survival MeSH
• Hedgehog Proteins genetics   MeSH
• Proto-Oncogene Proteins p21(ras) genetics   MeSH
• Aged MeSH
• Taxoids administration & dosage   therapeutic use   MeSH
• Transcriptome drug effects   MeSH
• Treatment Outcome MeSH
• Xenograft Model Antitumor Assays MeSH
• Animals MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• KRAS protein, human MeSH Browser
• Hedgehog Proteins MeSH
• Proto-Oncogene Proteins p21(ras) MeSH
• Taxoids MeSH

BACKGROUND: This study addresses involvement of major 5-fluorouracil (5-FU) pathway genes in the prognosis of colorectal carcinoma patients. METHODS: Testing set and two validation sets comprising paired tumor and adjacent mucosa tissue samples from 151 patients were used for transcript profiling of 15 5-FU pathway genes by quantitative real-time PCR and DNA methylation profiling by high resolution melting analysis. Intratumoral molecular profiles were correlated with clinical data of patients. Protein levels of two most relevant candidate markers were assessed by immunoblotting. RESULTS: Downregulation of DPYD and upregulation of PPAT, UMPS, RRM2, and SLC29A1 transcripts were found in tumors compared to adjacent mucosa in testing and validation sets of patients. Low RRM2 transcript level significantly associated with poor response to the first-line palliative 5-FU-based chemotherapy in the testing set and with poor disease-free interval of patients in the validation set irrespective of 5-FU treatment. UPP2 was strongly methylated while its transcript absent in both tumors and adjacent mucosa. DPYS methylation level was significantly higher in tumor tissues compared to adjacent mucosa samples. Low intratumoral level of UPB1 methylation was prognostic for poor disease-free interval of the patients (P = 0.0002). The rest of the studied 5-FU genes were not methylated in tumors or adjacent mucosa. CONCLUSIONS: The observed overexpression of several 5-FU activating genes and DPYD downregulation deduce that chemotherapy naïve colorectal tumors share favorable gene expression profile for 5-FU therapy. Low RRM2 transcript and UPB1 methylation levels present separate poor prognosis factors for colorectal carcinoma patients and should be further investigated.

• Keywords
• 5-fluorouracil, Colorectal carcinoma, Expression, Methylation, Prognosis,
• MeSH
• CpG Islands MeSH
• Fluorouracil pharmacology   MeSH
• Colorectal Neoplasms genetics   metabolism   mortality   pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• DNA Methylation MeSH
• Promoter Regions, Genetic MeSH
• Antimetabolites, Antineoplastic pharmacology   MeSH
• Gene Expression Regulation, Neoplastic drug effects   MeSH
• Ribonucleoside Diphosphate Reductase genetics   metabolism   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Signal Transduction drug effects   MeSH
• Neoplasm Staging MeSH
• Gene Expression Profiling * MeSH
• Neoplasm Grading MeSH
• Transcriptome * MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Fluorouracil MeSH
• Antimetabolites, Antineoplastic MeSH
• ribonucleotide reductase M2 MeSH Browser
• Ribonucleoside Diphosphate Reductase MeSH