All-trans-retinoic acid inhibits tumour growth of malignant pleural mesothelioma in mice

Oral encapsulated transforming growth factor β1 reduces endogenous levels: Effect on inflammatory bowel disease

BACKGROUND

TreXTAM^® is a combination of the key regulatory cytokine transforming growth factor beta (TGFβ) and all trans retinoic acid (ATRA) microencapsulated for oral delivery to immune structures of the gut. It is in development as a novel treatment for inflammatory bowel disease (IBD).

AIM

To measure TGFβ levels in blood and tissue after oral administration of encapsulated TGFβ.

METHODS

Animals were orally administered encapsulated TGFβ by gavage. Levels of drug substance in blood and in gut tissues at various times after administration were measured by ELISA.

RESULTS

We made the surprising discovery that oral administration of TreXTAM dramatically (approximately 50%) and significantly (P = 0.025) reduced TGFβ levels in colon, but not small intestine or mesenteric lymph nodes. Similarly, levels in rat serum after 25 d of thrice weekly dosing with either TreXTAM, or microencapsulated TGFβ alone (denoted as TPX6001) were significantly (P < 0.01) reduced from baseline levels. When tested in the SCID mouse CD4+CD25- adoptive cell transfer (ACT) model of IBD, oral TPX6001 alone provided only a transient benefit in terms of reduced weight loss.

CONCLUSION

These observations suggest a negative feedback mechanism in the gut whereby local delivery of TGFβ results in reduced local and systemic levels of the active form of TGFβ. Our findings suggest potential clinical implications for use of encapsulated TGFβ, perhaps in the context of IBD and/or other instances of fibrosis and/or pathological TGFβ signaling.

All-Trans Retinoic Acid Inhibits Migration and Invasiveness of Rheumatoid Fibroblast-Like Synoviocytes

Fibroblast-like synoviocytes (FLSs) are pivotal in inflammation and joint damage of rheumatoid arthritis (RA). They acquire an active and aggressive phenotype, displaying increased migration and invasiveness and contributing to perpetuate synovial inflammation and destruction of cartilage and bone. The main current therapies of RA are focused against inflammatory factors and immune cells; however, a significant percentage of patients do not successfully respond. Combined treatments with drugs that control inflammation and that reverse the pathogenic phenotype of FLS could improve the prognosis of these patients. An unexplored area includes the retinoic acid, the main biologic retinoid, which is a candidate drug for many diseases but has reached clinical use only for a few. Here, we explored the effect of all-trans retinoic acid (ATRA) on the aggressive phenotype of FLS from patients with RA. RA FLSs were treated with ATRA, tumor necrosis factor (TNF), or TNF+ATRA, and cell migration and invasion were analyzed. In addition, a microarray analysis of expression, followed by gene-set analysis and quantitative polymerase chain reaction validation, was performed. We showed that ATRA induced a notable decrease in FLS migration and invasion that was accompanied by complex changes in gene expression. At supraphysiological doses, many of these effects were overridden or reverted by the concomitant presence of TNF. In conclusion, these results have demonstrated the therapeutic potential of retinoic acid on RA FLS provided TNF could be counterbalanced, either with high ATRA doses or with TNF inhibitors. SIGNIFICANCE STATEMENT: All-trans retinoic acid (ATRA) reduced the rheumatoid arthritis (RA) fibroblast-like synoviocyte migration and invasiveness and down-regulated gene expression of cell motility and migration genes. At supraphysiological doses, some of these effects were reverted by tumor necrosis factor. Therefore, ATRA could be an RA drug candidate that would require high doses or combined treatment with anti-inflammatory drugs.

Genistein Affects Expression of Cytochrome P450 (CYP450) Genes in Hepatocellular Carcinoma (HEPG2/C3A) Cell Line

BACKGROUND

Genistein (5,7-Dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is the most abundant isoflavone in soybean, which has been associated with a lower risk of development of cancer and cardiovascular diseases. Of particular interest regarding cancer preventive properties of flavonoids is their interaction with cytochrome P450 enzymes (CYPs). However, contradictory data report the effect of genistein on expression of СYPs enzymes.

OBJECTIVE

The aim of this study was to investigate the effects of genistein on cytochrome P450 (CYP) gene expression levels in human hepatocellular carcinoma (HepG2/C3A) and colon adenocarcinoma (HT29) cells.

METHODS

Real-time RT-PCR was used to examine the expression of genes families involved in xenobiotic metabolism, such as CYP1 (CYP1A1, CYP1B1), CYP2 (CYP2E1, CYP2D6), CYP3 (CYP3A4); and of a family involved in the catabolism of the all-trans-retinoic acid (ATRA), CYP26 (CYP26A1, CYP26B1).

RESULTS

RT-qPCR data analysis showed that after 12 h of exposure of HepG2/C3A cells to genistein (5 and 50 µM) there was an upregulation of CYP1A1 and CYP1B1 and downregulation of CYP2D6, CYP26A1 and CYP26B1 mRNA levels. There was no change in the mRNA levels of CYP P450 genes in HT29 cells.

CONCLUSION

Our results suggest that treatment with genistein in non-toxic concentrations may impact the expression level of CYPs involved in the biotransformation of xenobiotics and drug metabolizing enzymes. Moreover, the downregulation of ATRA metabolism-related genes opens a new research path for the study of genistein as retinoic acid metabolism blocking agent for treating cancer and other pathologies.

The Use of Chemical-Chemical Interaction and Chemical Structure to Identify New Candidate Chemicals Related to Lung Cancer

Lung cancer causes over one million deaths every year worldwide. However, prevention and treatment methods for this serious disease are limited. The identification of new chemicals related to lung cancer may aid in disease prevention and the design of more effective treatments. This study employed a weighted network, constructed using chemical-chemical interaction information, to identify new chemicals related to two types of lung cancer: non-small lung cancer and small-cell lung cancer. Then, a randomization test as well as chemical-chemical interaction and chemical structure information were utilized to make further selections. A final analysis of these new chemicals in the context of the current literature indicates that several chemicals are strongly linked to lung cancer.

Preclinical Evaluation of a Novel RXR Agonist for the Treatment of Neuroblastoma

Neuroblastoma remains a common cause of pediatric cancer deaths, especially for children who present with advanced stage or recurrent disease. Currently, retinoic acid therapy is used as maintenance treatment to induce differentiation and reduce tumor recurrence following induction therapy for neuroblastoma, but unavoidable side effects are seen. A novel retinoid, UAB30, has been shown to generate negligible toxicities. In the current study, we hypothesized that UAB30 would have a significant impact on multiple neuroblastoma cell lines in vitro and in vivo. Cellular survival, cell-cycle analysis, migration, and invasion were studied using AlamarBlue assays, FACS, and Transwell assays, respectively, in multiple cell lines following treatment with UAB30. In addition, an in vivo murine model of human neuroblastoma was utilized to study the effects of UAB30 upon tumor xenograft growth and animal survival. We successfully demonstrated decreased cellular survival, invasion, and migration, cell-cycle arrest, and increased apoptosis after treatment with UAB30. Furthermore, inhibition of tumor growth and increased survival was observed in a murine neuroblastoma xenograft model. The results of these in vitro and in vivo studies suggest a potential therapeutic role for the low toxicity synthetic retinoid X receptor selective agonist, UAB30, in neuroblastoma treatment.

Retinoid and TGF-β families: crosstalk in development, neoplasia, immunity, and tissue repair

Transforming growth factor-β (TGF-β) isoforms are profibrotic cytokines, par excellence, and have complex multifunctional effects on many systems, depending on the biologic setting. Retinoids are vitamin A derivatives that also have diverse effects in development, physiology, and disease. The interactions between these classes of molecules are, not surprisingly, highly complex and are dependent on the tissue, cellular, and molecular settings.

Clinical role of pleural effusion MMP-3 levels in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor of mesothelial origin associated with asbestos exposure. MPM exhibits a limited response to conventional chemotherapy and radiotherapy. This, early diagnosis of MPM is essential. Malignant tumor progression requires the destruction of the basement membrane, which is constructed from extracellular matrix (ECM) materials. Various types of human tumor cells are reported to produce ECM-degrading proteases that are important in tumor progression. Among this group of proteolytic enzymes, matrix metalloproteinases (MMPs) are thought to be important due to their wide degrading function. We investigated the pleural effusion MMP-3 levels of patients with MPM and compared them with those of a population with non-malignant pleuritis or lung cancer involving malignant pleural effusion. The pleural effusion MMP-3 concentrations of 52 MPM patients and 67 non-MPM patients were measured. The results showed that the MPM patients had significantly higher pleural effusion MMP-3 levels than the population with non-malignant pleuritis. The overall survival of the MPM patients with lower pleural effusion MMP-3 levels was longer than that of patients with higher pleural effusion MMP-3 levels. Our data therefore suggest a clinical role of pleural effusion MMP-3 levels in malignant pleural mesothelioma.

Clinical significance of pleural effusion mesothelin in malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor of mesothelial origin associated with asbestos exposure. MPM has a limited response to conventional chemotherapy and radiotherapy, so early diagnosis of MPM is very important. This study investigated the pleural effusion mesothelin levels in patients with MPM and compared them to those of a population with a non-malignant pleuritis or lung cancer involving malignant pleural effusion.

METHODS

The pleural effusion mesothelin concentrations were measured in 45 MPM patients and 53 non-MPM individuals (24 individuals with non-malignant pleural effusions and 29 individuals with lung cancer involving malignant pleural effusion).

RESULTS

This study demonstrated that patients with MPM had significantly higher pleural effusion mesothelin levels than a population with non-malignant pleuritis or lung cancer involving malignant pleural effusion. The difference in overall survival between the groups with pleural effusion mesothelin levels lower and higher than the assumed cut-off of 10 nM was significant.

CONCLUSIONS

The data suggest that the pleural effusion mesothelin concentration could be useful as an aid for the diagnosis of MPM.

The calpain inhibitor calpeptin prevents bleomycin-induced pulmonary fibrosis in mice

Pulmonary fibrosis is characterized by progressive worsening of pulmonary function leading to a high incidence of death. Currently, however, there has been little progress in therapeutic strategies for pulmonary fibrosis. There have been several reports on cytokines being associated with lung fibrosis, including interleukin (IL)-6 and transforming growth factor (TGF)-β1. We reported recently that two substances (ATRA and thalidomide) have preventive effects on pulmonary fibrosis by inhibiting IL-6-dependent proliferation and TGF-β1-dependent transdifferentiation of lung fibroblasts. Rheumatoid arthritis is a chronic autoimmune disorder, and its pathogenesis is also characterized by an association with several cytokines. It has been reported that calpain, a calcium-dependent intracellular cysteine protease, plays an important role in the progression of rheumatoid arthritis. In this study, we examined the preventive effect of Calpeptin, a calpain inhibitor, on bleomycin-induced pulmonary fibrosis. We performed histological examinations and quantitative measurements of IL-6, TGF-β1, collagen type Iα1 and angiopoietin-1 in bleomycin-treated mouse lung tissues with or without the administration of Calpeptin. Calpeptin histologically ameliorated bleomycin-induced pulmonary fibrosis in mice. Calpeptin decreased the expression of IL-6, TGF-β1, angiopoietin-1 and collagen type Iα1 mRNA in mouse lung tissues. In vitro studies disclosed that Calpeptin reduced (i) production of IL-6, TGF-β1, angiopoietin-1 and collagen synthesis from lung fibroblasts; and (ii) both IL-6-dependent proliferation and angiopoietin-1-dependent migration of the cells, which could be the mechanism underlying the preventive effect of Calpeptin on pulmonary fibrosis. These data suggest the clinical use of Calpeptin for the prevention of pulmonary fibrosis.

Genomic abnormalities and signal transduction dysregulation in malignant mesothelioma cells

Malignant mesothelioma (MM) is a tumor with poor prognosis associated with asbestos exposure. While it remains to be clarified how asbestos fibers confer genetic/epigenetic alterations and induce cellular transformation in normal mesothelial cells, the understanding of key molecular mechanisms of MM cell development, proliferation, and invasion has progressed. MM shows frequent genetic inactivation of tumor suppressor genes of p16(INK4a)/p14(ARF) and neurofibromatosis type 2 (NF2) which encodes Merlin, and epigenetic inactivation of RASSF1A. However, no frequent mutations of well-known oncogenes such as K-RAS and PIK3CA have been identified. Activation of multiple receptor tyrosine kinases including the epidermal growth factor receptor (EGFR) family and MET, and subsequent deregulations of mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K)-AKT signaling cascades are frequently observed in most MM cells. The tumor suppressive function of Merlin in MM cells is also being investigated by dissecting its possible downstream signaling cascade called the Hippo pathway. Further comprehensive delineation of dysregulated signaling cascades in MM cells will lead to identification of key addiction pathways for cell survival and proliferation of MM cells, which strongly promote establishment of a new molecular target therapy for MM.