PRELIMINARY SCREENING OF PHYTOCHEMICALS AND ANTIPROLIFERATIVE AND ANTI-INFLAMMATORY PROPERTIES OF THESPESIA POPULNEA (L.) SOLAND LEAF EXTRACTS

Objective: Plant-derived bioactive molecules are providing infinite opportunities for new drug development as they possess a wide range of actions against diseases with lesser side effects. The present study is made to analyze the qualitative phytochemicals and to evaluate in vitro antiproliferative and anti-inflammatory potentials of leaf extracts of Thespesia populnea. Methods: T. populnea leaf extracts were prepared sequentially according to the increasing polarity of the solvents, i.e., petroleum ether, chloroform, ethyl acetate, and methanol. Qualitative phytochemical analysis was performed to identify the chemical constituents of the extracts, and antiproliferative properties were evaluated against different cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. Bovine serum albumin anti-denaturation assay was done to identify the anti-inflammatory activity.Results: Phytochemical analysis of the extracts revealed the presence of alkaloids, terpenoids, glycosides, tannins, flavonoids, and phenolics. The chloroform extract (CHFE) of T. populnea has a dose-dependent antiproliferative effect against acute T-cell leukemia (Jurkat E6-1), prostate Grade IV adenocarcinoma (PC-3), mouse fibroblast (L-929), and monkey kidney normal (Vero) cells. Their inhibitory concentration 50% (IC50) values were found to be 35.73±0.94 μg/ml for Jurkat E6-1, 60.79±1.84 μg/ml for PC-3, 60.88±1.45 μg/ml for L-929, and 83.482±2.05 μg/ml for Vero, respectively. CHFE also displayed the anti-inflammatory potential.Conclusion: The chloroform leaf extract of T. populnea possesses potent antiproliferative and anti-inflammatory activity. These properties present in leaf extract may be explained by the presence of biologically active constituents

Cell–cell adhesion: linking Wnt/β-catenin signaling with partial EMT and stemness traits in tumorigenesis [version 1; referees: 4 approved]

Changes in cell adhesion and motility are considered key elements in determining the development of invasive and metastatic tumors. Co-opting the epithelial-to-mesenchymal transition (EMT) process, which is known to occur during embryonic development, and the associated changes in cell adhesion properties in cancer cells are considered major routes for tumor progression. More recent in vivo studies in tumor tissues and circulating tumor cell clusters suggest a stepwise EMT process rather than an “all-or-none” transition during tumor progression. In this commentary, we addressed the molecular mechanisms underlying the changes in cell adhesion and motility and adhesion-mediated signaling and their relationships to the partial EMT states and the acquisition of stemness traits by cancer cells

The Collagen-Modifying Enzyme PLOD2 Is Induced and Required during L1-Mediated Colon Cancer Progression

The overactivation of Wnt/β-catenin signaling is a hallmark of colorectal cancer (CRC) development. We identified the cell adhesion molecule L1CAM (L1) as a target of β-catenin-TCF transactivation in CRC cells. The overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis and liver metastasis, and L1 is exclusively localized in the invasive areas of human CRC tissue. A number of genes are induced after L1 transfection into CRC cells by a mechanism involving the cytoskeletal protein ezrin and the NF-κB pathway. When studying the changes in gene expression in CRC cells overexpressing L1 in which ezrin levels were suppressed by shRNA to ezrin, we discovered the collagen-modifying enzyme lysyl hydroxylase 2 (PLOD2) among these genes. We found that increased PLOD2 expression was required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis and liver metastasis, since the suppression of endogenous PLOD2 expression, or its enzymatic activity, blocked the enhanced tumorigenic properties conferred by L1. The mechanism involved in increased PLOD2 expression by L1 involves ezrin signaling and PLOD2 that affect the SMAD2/3 pathway. We found that PLOD2 is localized in the colonic crypts in the stem cell compartment of the normal mucosa and is found at increased levels in invasive areas of the tumor and, in some cases, throughout the tumor tissue. The therapeutic strategies to target PLOD2 expression might provide a useful approach for CRC treatment

Wnt/β-Catenin Target Genes in Colon Cancer Metastasis: The Special Case of L1CAM

Cell adhesion to neighboring cells is a fundamental biological process in multicellular organisms that is required for tissue morphogenesis. A tight coordination between cell–cell adhesion, signaling, and gene expression is a characteristic feature of normal tissues. Changes, and often disruption of this coordination, are common during invasive and metastatic cancer development. The Wnt/β-catenin signaling pathway is an excellent model for studying the role of adhesion-mediated signaling in colorectal cancer (CRC) invasion and metastasis, because β-catenin has a dual role in the cell; it is a major adhesion linker of cadherin transmembrane receptors to the cytoskeleton and, in addition, it is also a key transducer of Wnt signaling to the nucleus, where it acts as a co-transcriptional activator of Wnt target genes. Hyperactivation of Wnt/β-catenin signaling is a common feature in the majority of CRC patients. We found that the neural cell adhesion receptor L1CAM (L1) is a target gene of β-catenin signaling and is induced in carcinoma cells of CRC patients, where it plays an important role in CRC metastasis. In this review, we will discuss studies on β-catenin target genes activated during CRC development (in particular, L1), the signaling pathways affected by L1, and the role of downstream target genes activated by L1 overexpression, especially those that are also part of the intestinal stem cell gene signature. As intestinal stem cells are highly regulated by Wnt signaling and are believed to also play major roles in CRC progression, unravelling the mechanisms underlying the regulation of these genes will shed light on both normal intestinal homeostasis and the development of invasive and metastatic CRC

Tetracycline and Glutathione Inhibit Matrix Metalloproteinase Activity: An In Vitro Study Using Culture Supernatants of L929 and Dalton Lymphoma Cell Lines

Tetracycline and glutathione inhibited the protease activities of matrix metalloproteinase-2 and matrix metalloproteinase-9 expressed by mouse fibrosarcoma cells (L929) and Dalton lymphoma cells, respectively. The inhibitory activity of the tetracycline may be due to its ability to chelate metal ions such as calcium and zinc. Gelatin-zymography technique was used to demonstrate the inhibitory activity of both tetracycline and glutathione. The intensity of the bands corresponding to metalloproteinase activity in zymography gel was reduced in the presence of 50–100 μg/mL of tetracycline. The presence of 10–100 μg/mL of tetracycline in the medium increased the adherence of L929 cancer cells. These results clearly indicate the antimetastatic property of tetracycline. Reduced glutathione, a compound which is produced endogenously by the cells to maintain the redox status, was shown to inhibit the matrix metalloproteinase activity (in vitro). Therefore, it is assumed that decreased glutathione levels in synovial fluids or plasma might increase the activity of MMP. Reduced glutathione at 100 μg/mL inhibited the metalloproteinase activity in gelatin-zymographic gel. As both tetracycline and glutathione exhibited an inhibitory effect on matrix metalloproteinase activity, it was of great interest to check their clinical effects on various MMP associated pathological conditions such as cancer metastasis and arthritis. Here we report that tetracycline and reduced glutathione inhibited the activity of MMP2 completely and activity of MMP9 partly

A Necessary Role for Increased Biglycan Expression during L1-Mediated Colon Cancer Progression

Aberrant activation of Wnt/β-catenin signaling and downstream β-catenin-TCF target genes is a hallmark of colorectal cancer (CRC) development. We identified the immunoglobulin-like cell adhesion receptor L1CAM (L1) as a target of β-catenin-TCF transactivation in CRC cells. Overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis, and liver metastasis, and L1 is exclusively localized at invasive areas of human CRC tissue. Several genes are induced after L1 transfection into CRC cells by a mechanism involving the L1-ezrin-NF-κB pathway. We conducted a secretomic analysis of the proteins in the culture medium of L1-overexpressing CRC cells. We detected a highly increased level of biglycan, a small leucine-rich ECM component, and a signaling molecule. We found that induction of biglycan is required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis, and liver metastasis. The suppression of endogenous biglycan levels or a point mutation in the L1 ectodomain that regulates cell–cell adhesion mediated by L1 blocked the enhanced tumorigenic properties conferred by L1. The mechanism of biglycan induction by L1 involves the L1-NF-κB pathway. Blocking NF-κB signaling in L1 expressing cells suppressed the induction of biglycan and the tumorigenic properties conferred by L1. Biglycan expression was undetectable in the normal colonic mucosa, but expressed at highly increased levels in the tumor tissue, especially in the stroma. The therapeutic strategies to target biglycan expression might provide a useful approach for CRC treatment in L1-overexpressing tumors

EVALUATION OF IN VITRO ANTICANCER AND ANTIOXIDANT ACTIVITIES FROM LEAF EXTRACTS OF MEDICINAL PLANT CLIDEMIA HIRTA

Objective: To evaluate the anticancer and antioxidant activity of medicinal plant Clidemia hirta extracted in different solvents.Methods: Crude extracts were prepared from the leaves of Clidemia hirta using ethanol, petroleum ether and chloroform solvents. Anticancer activities and antioxidant properties were assayed using standard yellow dye 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and 1, 1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging assay respectively.Results: We found that the ethanol extract had higher inhibition activities against Dalton's lymphoma ascites (DLA) cancer cell line, 50% DLA cell line inhibition at 68µg/ml, while 50% inhibition by petroleum ether and chloroform extracts were at 160µg/ml and 172µg/ml, respectively. The antioxidant activity requires5µg/ml of ethanol extract to trap 50% of DPPH (IC50), whereas the positive control ascorbic acid trapped 50% of DPPH (IC50) at 3.5µg/ml.Conclusion: The prepared leaf extracts with different solvents of Clidemia hirta showed the antiproliferative and antioxidant activity in dose-dependent manner. Further works is required to identify the biologically active chemical constituents, responsible for cancer cell growth inhibition from this plant