alitretinoin and Adenocarcinoma

Retinoids, acting through their cognate nuclear receptors, are crucial transcriptional regulators of many cellular processes such as differentiation, development, apoptosis, carbohydrate and lipid metabolism, homeostasis, etc. The aim of this study was the exploration of molecular mechanisms in relation to therapy of human breast cancer. One of the efficient strategies is identification of biomarkers as important tools in early cancer diagnosis and advisable treatment. Retinoids have been regarded as important therapeutic agents for many types of cancers, including human breast cancer. The effects of all-trans retinoic acid and 9-cis retinoic acid or their combination on proteomic pattern in human MCF-7 breast cancer line were investigated. The total cell proteins were extracted utilizing a commercially Radio-Immunoprecipitation Assay (RIPA) buffer and separated on 1D sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE). The proteins were subsequently digested in-gel by trypsin and identified by matrix assisted laser desorption ionization technique with time of flight mass analyzer (MALDI-TOF/TOF). Our data offer novel information on the proteomic pattern of proteins evaluated after treatment of MCF-7 cells with retinoic acid isomers.

Topics: Adenocarcinoma; Alitretinoin; Amino Acid Sequence; Antineoplastic Agents; Breast Neoplasms; Female; HSP90 Heat-Shock Proteins; Humans; Isomerism; MCF-7 Cells; Molecular Sequence Data; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tretinoin

Previous research has shown that the retinoid 9-cis retinoic acid (RA) promotes apoptosis in pancreatic cancer cells. The vitamin D analog EB1089 does not. Furthermore, cotreatment of cells with 9-cis RA and EB1089 abrogates apoptosis. To explain this, we studied the regulation of proteins involved in apoptotic signaling pathways in pancreatic cancer cells.. The pancreatic adenocarcinoma cell line T3M4 was used. Cell proliferation was measured using the SRB protein dye assay. Induction of apoptosis was evaluated using an ELISA assay. Caspase activation was detected using a colorimetric assay based on cleavage of a caspase-associated substrate. Regulation of protein levels and posttranslational events were detected using immunoblotting.. We confirm that EB1089 diminishes apoptosis induced by 9-cis RA in T3M4 cells. We extend the study to show that EB1089 abrogates increases, induced by 9-cis RA, in caspase activation, p27Kip1 protein levels, Bim and Bax protein levels and in Bax/Bcl2 ratio. In addition, the CDKI p21Waf1 and CAII, a differentiation marker for pancreatic cancer cells are also differentially regulated.. These results suggest that the inhibitory effects of EB1089 on 9-cis RA-induced apoptosis lie upstream of caspase activation and could be associated with reduction of p27Kip1 protein levels.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Apoptosis; Calcitriol; Caspases; Cell Division; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p27; Enzyme-Linked Immunosorbent Assay; Humans; Pancreatic Neoplasms; Tretinoin

Lung cancer is the leading cause of cancer death worldwide. A diet rich in fruit and vegetables has been shown to reduce the lung cancer risk. However, clinical trials with beta-carotene and retinoids have disappointed, resulted in increased mortality from lung cancer and cardiovascular disease.. We have investigated the effects of the two major retinol metabolites, 9-cis-retinoic acid (9-Cis-RA), and 13-cis-retinoic acid (13-Cis-RA), on cell proliferation (MTT assays), intracellular cAMP (cAMP immunoassays), PKA activation (non-radioactive PKA activation assays), and ERK1/2 phosphorylation (Western blots) in immortalized human small airway epithelial cells, HPL1D, a human lung adenocarcinoma cell line, NCI-H322, immortalized human bronchial epithelial cells, BEAS-2B, and in the human small cell lung carcinoma cell line, NCI-H69.. Both retinoids increased intracellular cAMP and PKA activation in all cell lines. In BEAS-2B and NCI-H69 cells, the stimulation of cAMP/PKA reduced the phosphorylation of ERK1/2 and inhibited cell proliferation whereas phosphorylation of ERK1/2 and cell proliferation were increased in HPL1D and NCI-H322 cells.. Our data have identified a novel mechanism of action of 9-Cis-RA and 13-Cis-RA: activation of PKA in response to increased cAMP. The observed stimulation of cAMP/PKA may inhibit the development of small cell lung carcinoma and other tumors derived from large airway epithelia whereas it may selectively promote the development of lung tumors derived from small airway epithelial cells, such as adenocarcinoma.

Topics: Adenocarcinoma; Alitretinoin; Blotting, Western; Bronchi; Carcinoma, Small Cell; Cell Proliferation; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Enzyme Activation; Epithelial Cells; Humans; Immunoassay; Isotretinoin; Lung Neoplasms; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Respiratory Mucosa; Signal Transduction; Tretinoin; Tumor Cells, Cultured

To study the effects of 9-cis-retinoic acid (9-cis-RA) on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells.. 9-cis-RA (1 x 10(-6) mol.L-1) was used to treat lung cancer cells for 24 h; Flow cytometry (FCM) was used to detect the percent of G0/G1 phase and S phase cells of three groups including blank control, DMSO control and 9-cis-RA groups; RT-PCR was used to analyze the expression changes of cyclin D1 and cdk4 before and after treatment with 9-cis-RA in lung cancer cells.. The percent of G0/G1 phase cells of 9-cis-RA groups was significantly higher than that of the control groups (P < 0.01 or P < 0.05) and the percent of S phase cells of 9-cis-RA groups was lower than that of the control groups (P < 0.01 or P < 0.05); the expression of cyclin D1 of PG, SPC-A1 and L78 cells was decreased (P < 0.01) and the expression of cdk4 of PG, A549 and L78 cells was also decreased (P < 0.01) after treatment with 9-cis-RA.. Most of the proliferation and the expression of cyclin D1 and cdk4 of PG, A549, SPC-A1 and L78 were inhibited by 9-cis-RA.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; G1 Phase; Humans; Lung Neoplasms; Proto-Oncogene Proteins; Resting Phase, Cell Cycle; S Phase; Tretinoin

Peroxisome prolixferator-activated receptor gamma (PPARgamma), a ligand-activated transcription factor, forms a heterodimer with retinoid X receptor alpha (RXRalpha), and its transcriptional activity is thought to be maximal in the presence of both PPARgamma and RXRalpha ligands. Although previous studies suggested that thiazolidinediones (TZDs), known as PPARgamma ligands, inhibit the growth of several types of tumor cells, the precise mechanism still remains obscure. The present study was designed to examine the effects of PPARgamma/RXRalpha transcriptional activation on cell growth in cancer cells. We compared the effects of six types of TZDs (troglitazone, RS-1303, RS-1330, RS-1387, RS-1455, and RS-1456) and 9-cis RA, an RXRalpha ligand, on the activation of PPARgamma/RXRalpha and the growth inhibition of six types of adenocarcinoma cell lines (MKN45, HT-29, HCT116, HuCCT1, KMP-2, and BxPC3) established from abdominal malignancies. PPARgamma was expressed in all six tumor cell lines and transcriptionally functional in five of the six lines. The stronger PPARgamma activator showed the stronger growth inhibitor in these five cell lines. However, no significant growth inhibitory effect of six types of PPARgamma activators was observed in BxPC3 cells, which showed no significant PPARgamma transactivation by these activators. Simultaneous addition of troglitazone and 9-cis RA enhanced both activation of PPARgamma/RXRalpha and growth inhibition in several types of cancer cells. The degree of PPARgamma/RXRalpha activation correlated with the extent of growth inhibition (r > 0.70, P < 0.05). This growth inhibition was associated with G1 cell cycle arrest and cell differentiation. These findings suggest that activation of the PPARgamma/RXRalpha pathway plays an important role in the growth inhibition of tumor cells and that this nuclear hormone receptor may be a possible novel molecular target for treatment of tumors in humans.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Apoptosis; Biliary Tract Neoplasms; Cell Differentiation; Cell Division; Chromans; Drug Screening Assays, Antitumor; Drug Synergism; Gastrointestinal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Receptors, Cytoplasmic and Nuclear; Receptors, Retinoic Acid; Retinoid X Receptors; Thiazoles; Thiazolidinediones; Transcription Factors; Transcriptional Activation; Tretinoin; Troglitazone; Tumor Cells, Cultured

Analogues of vitamin A have been shown to influence growth of malignant tissue, such as pancreatic cancer.. To study the expression of retinoic acid receptors (RAR) in pancreatic cancer cells and the effect of three different retinoids on the cell number in vitro were studied.. Cell lines were established from 13 patients who underwent surgery for pancreatic adenocarcinoma. The expression of the retinoic acid receptors (RAR) and retinoic X receptor (RXR) subtypes (alpha, beta, and gamma) was studied with western blotting and specific antibodies. The effect of incubation with all-trans-retinoic acid (atRA; tretinoin), 9-cis-retinoic acid (9-cis-RA), and 13-cis-retinoic acid (13-cis-RA; isotretinoin) on the cell number was examined with use of a Roche XTT cell proliferation kit.. The RXR alpha receptor was expressed in all cell lines. RAR alpha,beta and RXR beta were expressed in most of them. RXR gamma was expressed in about half of the cell lines and RAR gamma in only one. Incubation of the cells with retinoids showed a decreased cell number at concentrations of 10(4) M, except for 9-cis-RA, to which only about half of the cell lines responded.. Two or more of the RAR subtypes were expressed in each pancreatic cell line. There was no uniform pattern of receptor expression; however, the cell lines responded with decreased cell number to high concentrations of atRA and 13-cis-RA but not to 9-cis-RA.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Blotting, Western; Cell Division; Dose-Response Relationship, Drug; Humans; In Vitro Techniques; Isotretinoin; Pancreatic Neoplasms; Receptors, Retinoic Acid; Retinoid X Receptors; Transcription Factors; Tretinoin; Tumor Cells, Cultured

All-trans-retinoic acid and 9-cis-retinoic acid have been reported to have inhibitory effects on pancreatic adenocarcinoma cells and we have shown that this is partly due to induction of apoptosis. In this study, the mechanisms whereby 9-cis-retinoic acid induces apoptosis in these cells were investigated. An involvement of the Bcl-2 family of proteins was shown, such that 9-cis-retinoic acid causes a decrease in the Bcl-2/Bax ratio. Overexpression of Bcl-2 also resulted in inhibition of apoptosis induced by 9-cis-retinoic acid. Furthermore, two broad-range caspase inhibitors blocked DNA fragmentation induced by 9-cis-retinoic acid, but had no effect on viability defined by mitochondrial activity. Using synthetic retinoids, which bind selectively to specific retinoic acid receptor subtypes, we further established that activation of retinoic acid receptor-gamma is essential for induction of apoptosis. Only pan-retinoic acid receptor and retinoic acid receptor-gamma selective agonists reduced viability and a cell line expressing very low levels of retinoic acid receptor-gamma is resistant to the effects of 9-cis-retinoic acid. A retinoic acid receptor-beta/gamma selective antagonist also suppressed the cytotoxic effects of 9-cis-retinoic acid in a dose-dependent manner. This study provides important insight into the mechanisms involved in suppression of pancreatic tumour cell growth by retinoids. Our results encourage further work evaluating the clinical use of receptor subtype selective retinoids in pancreatic carcinoma.

Topics: Adenocarcinoma; Alitretinoin; Amino Acid Chloromethyl Ketones; Animals; Apoptosis; Aspartic Acid; bcl-2-Associated X Protein; Cysteine Proteinase Inhibitors; DNA Fragmentation; Drug Resistance; Fatty Acids, Unsaturated; Gene Expression Regulation, Neoplastic; Genes, bcl-2; Humans; Mice; Mitochondria; Neoplasm Proteins; Pancreatic Neoplasms; Protein Isoforms; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Receptors, Retinoic Acid; Recombinant Fusion Proteins; Retinoic Acid Receptor gamma; Retinoid X Receptors; Retinoids; Transcription Factors; Transfection; Tretinoin; Tumor Cells, Cultured

In experimental trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model, a significant decrease in tumor incidence (to 5%) was observed in rats treated with melatonin and 9-cis-retinoic acid (9 cRA) compared to controls (55%). Although 9cRA alone decreased tumor incidence to 26%, this response did not reach statistical significance. Tumor incidence was significantly inhibited to 20% in the animals that received melatonin and 9cRA on alternating days. Latency to tumor onset was prolonged in animals receiving either of the combination treatments compared with controls, and tumor multiplicity was also significantly decreased.

Topics: Adenocarcinoma; Alitretinoin; Animals; Anticarcinogenic Agents; Antioxidants; Body Weight; Carcinogens; Drug Synergism; Drug Therapy, Combination; Estradiol; Estrogen Receptor alpha; Female; Free Radical Scavengers; Mammary Neoplasms, Experimental; Melatonin; Methylnitrosourea; Organ Size; Rats; Rats, Sprague-Dawley; Receptors, Estrogen; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Tretinoin; Uterus

Retinoids, which are derivatives of vitamin A, are important factors involved in the control of biologic functions such as cell growth and differentiation, development, and carcinogenesis. We have shown previously that the naturally occurring retinoids all-trans-retinoic acid (ATRA) and 9-cisretinoic acid (9cRA) induce growth inhibition followed by apoptosis in pancreatic adenocarcinoma cells in vitro.. To evaluate the efficacy of retinoids in combination with the chemotherapeutic drugs gemcitabine and cisplatin.. In vitro growth inhibition and induction of apoptosis by different combinations of retinoids and cytotoxic drugs were studied by using the T3M-4 and BxPc-3 cell lines. For in vivo studies, T3M-4 cells were injected subcutaneously in nude mice.. Pre-treatment of pancreatic adenocarcinoma cells with ATRA or 9cRA before the addition of the drugs resulted in significant reduction in cell number compared with treatment with the drugs alone. Pre-treatment with 9cRA followed by gemcitabine or cisplatin alone also resulted in a strong increase in the percentage of cells undergoing programmed cell death, or apoptosis. Furthermore, there was an indication that the combination of ATRA and gemcitabine caused increased apoptosis in vivo.. Our results clearly suggest the need for additional studies exploring the potential role of the combination of retinoids and gemcitabine in the management of pancreatic cancer.

Topics: Adenocarcinoma; Alitretinoin; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cisplatin; Deoxycytidine; Drug Synergism; Female; Gemcitabine; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Tretinoin; Tumor Cells, Cultured

The effects of retinoic acid (RA) and its analogs, all-trans RA, 9-cis RA and 13-cis RA, were investigated in human breast cancer MCF-7 cells and immortalized breast epithelial cell line MCF-10A. RA inhibited the telomerase activity of MCF-7 cells in a wide range of concentrations. RA at 10 microM also inhibited the growth of MCF-7 cells in a time-dependent manner. However, no significant growth inhibition was found between untreated control and RA-treated MCF-10A cells. Moreover, a marked inhibition of telomerase activity by RA was detected early in MCF-7 cells (after 24 h of RA treatment), which was preceded by a reduction of hTERT mRNA expression (after 12 h of RA treatment). However, MCF-10A cells showed a reduction of telomerase activity and down-regulation of hTERT after 4 days of RA treatment. Simultaneous changes in hTERT mRNA expression and telomerase activity were found for MCF-10A cells. The expressions of hTR and hTEP1 telomerase component genes were not changed after RA treatment. These results indicate that the anti-breast cancer activity of RA could be mediated by its ability to down-regulate the expression of hTERT telomerase gene.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Breast Neoplasms; Enzyme Induction; Female; Gene Expression Regulation, Neoplastic; Humans; Isotretinoin; Neoplasm Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Telomerase; Tretinoin; Tumor Cells, Cultured

Topics: Adenocarcinoma; Alitretinoin; Animals; Anticarcinogenic Agents; Female; Mammary Neoplasms, Experimental; Melatonin; Methylnitrosourea; Rats; Rats, Sprague-Dawley; Tretinoin

Surfactant-associated proteins (SP) play an important role in the function of pulmonary surfactant. We have previously shown that SP-B mRNA is increased whereas SP-A and SP-C mRNA are decreased by all-trans-retinoic acid (RA) in a dose-dependent manner in human fetal lung explants. All-trans-RA binds primarily to the retinoic acid receptors (RARs) and 9-cis-RA binds primarily to the retinoid X receptors (RXRs). Because the fetal lung contains RXRs, we hypothesized that 9-cis-RA regulates surfactant protein gene expression in lung epithelial cells. H441 human lung adenocarcinoma cells, which synthesize SP-A and SP-B mRNA and protein, were treated with either all-trans-RA or 9-cis-RA (10(-10) to 10(-6) M) for 24 h. Neither all-trans-RA nor 9-cis-RA had an effect on SP-A mRNA levels in the H441 cells. All-trans-RA (10(-6) M) significantly increased SP-B mRNA levels in the H441 cells and 9-cis-RA had a smaller, not statistically significant effect. Human fetal lung explants were treated with 9-cis-RA for 6 d. 9-cis-RA did not significantly increase SP-B mRNA levels, significantly inhibited SP-A mRNA levels at all concentrations tested, and significantly inhibited SP-C mRNA levels at 10(-6) M in the human fetal lung explants. Both all-trans-RA (10(-6) M) and 9-cis-RA (10(-6) M) significantly increased SP-B protein levels in the human fetal lung explants. Together, these results are suggestive that all-trans-RA directly regulates SP-B gene expression in human pulmonary epithelial cells. In addition, the inhibitory effect of all-trans-RA and 9-cis-RA on SP-A mRNA levels in pulmonary epithelial cells is probably an indirect effect mediated by other cell types present in fetal lung tissue.

Topics: Adenocarcinoma; Alitretinoin; Analysis of Variance; Humans; Kinetics; Lung; Lung Neoplasms; Organ Culture Techniques; Proteolipids; Pulmonary Surfactant-Associated Protein A; Pulmonary Surfactant-Associated Proteins; Pulmonary Surfactants; Receptors, Retinoic Acid; Retinoid X Receptors; RNA, Messenger; Transcription Factors; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured

The effect of 9-cis-retinoic acid (9-cis-RA) on the growth of eight gastric cancer cell lines was related to their transcription levels of mRNAs for retinoid receptors. Northern blot analysis showed that seven (TMK-1, MKN-1, -28, -45, -74, HSC-39, KATO-III) out of eight gastric cancer cell lines synthesized mRNAs for retinoic acid receptors (RARs) and retinoid X receptor-alpha (RXR-alpha). MKN-7 cells did not transcribe either RARs or RXR-alpha at the mRNA level although they appeared to have no alterations at the gene level. The growth of all of the cell lines except for MKN-7 cells was inhibited by 1 x 10(-6) M 9-cis-RA. Cell cycle distribution analysis revealed that G0-G1 arrest was not induced by exposure to 9-cis-RA in the sensitive TMK-1 and KATO-III cells or the resistant MKN-7 cells. Interestingly, 9-cis-RA temporarily increased the amount of the cyclin dependent kinase (cdk) inhibitor, Waf1/Cip1/Sdi1/p21 protein, and also reduced the amount of cdk-7, epidermal growth factor receptor (EGFR) and cyclin D1 proteins, followed by reduction in phosphorylation of the product of the retinoblastoma tumor suppressor gene (Rb) in the sensitive TMK-1 cells, but not in the resistant MKN-7 cells. These results suggest that 9-cis-RA has a cytostatic effect on gastric cancer cells that synthesize the receptor molecules through cell cycle regulatory machinery.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Cell Cycle; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Humans; Receptors, Retinoic Acid; Retinoid X Receptors; RNA, Messenger; Signal Transduction; Stomach Neoplasms; Transcription Factors; Tretinoin; Tumor Cells, Cultured