Suppression of matrix metalloproteinase-2 via RNA interference inhibits pancreatic carcinoma cell invasiveness and adhesion

Novel sights on therapeutic, prognostic, and diagnostics aspects of non-coding RNAs in glioblastoma multiforme

Glioblastoma Multiforme (GBM) is the primary brain tumor and accounts for 200,000 deaths each year worldwide. The standard therapy includes surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiotherapy. The survival period of GBM patients is only 12-15 months. Therefore, novel treatment modalities for GBM treatment are urgently needed. Mounting evidence reveals that non-coding RNAs (ncRNAs) were involved in regulating gene expression, the pathophysiology of GBM, and enhancing therapeutic outcomes. The combinatory use of ncRNAs, chemotherapeutic drugs, and tumor suppressor gene expression induction might provide an innovative, alternative therapeutic approach for managing GBM. Studies have highlighted the role of Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in prognosis and diagnosis. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Studies have also indicated the blood-brain barrier (BBB) as a crucial factor that hinders chemotherapy. Although several nanoparticle-mediated drug deliveries were degrading effectively against GBM in vitro conditions. However, the potential to cross the BBB and optimum delivery of oligonucleotide RNA into GBM cells in the brain is currently under intense clinical trials. Despite several advances in molecular pathogenesis, GBM remains resistant to chemo and radiotherapy. Targeted therapies have less clinical benefit due to high genetic heterogeneity and activation of alternative pathways. Thus, identifying GBM-specific prognostic pathways, essential genes, and genomic aberrations provide several potential benefits as subtypes of GBM. Also, these approaches will provide insights into new strategies to overcome the heterogenous nature of GBM, which will eventually lead to successful therapeutic interventions toward precision medicine and precision oncology.

Extracellular Hsp70 Reduces the Pro-Tumor Capacity of Monocytes/Macrophages Co-Cultivated with Cancer Cells

Cancer cells are known to contain high levels of the heat shock protein 70 kDa (Hsp70), which mediates increased cell proliferation, escape from programmed cell death, enhanced invasion, and metastasis. A part of Hsp70 molecules may release from cancer cells and affect the behavior of adjacent stromal cells. To explore the effects of Hsp70 on the status of monocytes/macrophages in the tumor locale, we incubated human carcinoma cells of three distinct lines with normal and reduced content of Hsp70 with THP1 monocytes. Using two methods, we showed that the cells with knock-down of Hsp70 released a lower amount of protein in the extracellular medium. Three cycles of the co-cultivation of cancer and monocytic cells led to the secretion of several cytokines typical of the tumor microenvironment (TME) and to pro-cancer activation of the monocytes/macrophages as established by elevation of F4/80 and arginase-1 markers. Unexpectedly, the efficacy of epithelial–mesenchymal transition and resistance of carcinoma cells to anticancer drugs after incubation with monocytic cells were more pronounced in cells with lower Hsp70, e.g., releasing less Hsp70 into the extracellular milieu. These data suggest that Hsp70 released from tumor cells into the TME is able, together with the development of an anti-cancer immune response, to limit the conversion of a considerable part of monocytic cells to the pro-tumor phenotype.

Nerves and Pancreatic Cancer: New Insights into a Dangerous Relationship

Perineural invasion (PNI) is defined as the presence of neoplastic cells along nerves and/or within the different layers of nervous fibers: epineural, perineural and endoneural spaces. In pancreatic cancer-particularly in pancreatic ductal adenocarcinoma (PDAC)-PNI has a prevalence between 70 and 100%, surpassing any other solid tumor. PNI has been detected in the early stages of pancreatic cancer and has been associated with pain, increased tumor recurrence and diminished overall survival. Such an early, invasive and recurrent phenomenon is probably crucial for tumor growth and metastasis. PNI is a still not a uniformly characterized event; usually it is described only dichotomously ("present" or "absent"). Recently, a more detailed scoring system for PNI has been proposed, though not specific for pancreatic cancer. Previous studies have implicated several molecules and pathways in PNI, among which are secreted neurotrophins, chemokines and inflammatory cells. However, the mechanisms underlying PNI are poorly understood and several aspects are actively being investigated. In this review, we will discuss the main molecules and signaling pathways implicated in PNI and their roles in the PDAC.

The long non-coding RNA HOTTIP enhances pancreatic cancer cell proliferation, survival and migration

HOTTIP is a long non-coding RNA (lncRNA) transcribed from the 5′ tip of the HOXA locus and is associated with the polycomb repressor complex 2 (PRC2) and WD repeat containing protein 5 (WDR5)/mixed lineage leukemia 1 (MLL1) chromatin modifying complexes. HOTTIP is expressed in pancreatic cancer cell lines and knockdown of HOTTIP by RNA interference (siHOTTIP) in Panc1 pancreatic cancer cells decreased proliferation, induced apoptosis and decreased migration. In Panc1 cells transfected with siHOTTIP, there was a decrease in expression of 757 genes and increased expression of 514 genes, and a limited gene analysis indicated that HOTTIP regulation of genes is complex. For example, Aurora kinase A, an important regulator of cell growth, is coregulated by MLL and not WDR5 and, in contrast to previous studies in liver cancer cells, HOTTIP does not regulate HOXA13 but plays a role in regulation of several other HOX genes including HOXA10, HOXB2, HOXA11, HOXA9 and HOXA1. Although HOTTIP and the HOX-associated lncRNA HOTAIR have similar pro-oncogenic functions, they regulate strikingly different sets of genes in Panc1 cells and in pancreatic tumors.

New insights into perineural invasion of pancreatic cancer: More than pain

Pancreatic cancer is one of the most malignant human tumors. Perineural invasion, whereby a cancer cell invades the perineural spaces surrounding nerves, is acknowledged as a gradual contributor to cancer aggressiveness. Furthermore, perineural invasion is considered one of the root causes of the recurrence and metastasis observed after pancreatic resection, and it is also an independent predictor of prognosis. Advanced research has demonstrated that the neural microenvironment is closely associated with perineural invasion in pancreatic cancer. Therapy targeting the molecular mechanism of perineural invasion may enable the durable clinical treatment of this formidable disease. This review provides an overview of the present status of perineural invasion, the relevant molecular mechanisms of perineural invasion, pain and hyperglycemia associated with perineural invasion in pancreatic cancer, and the targeted therapeutics based on these studies.

Silencing Matrix Metalloproteinases 9 and 2 Inhibits Human Retinal Microvascular Endothelial Cell Invasion and Migration

PURPOSE

Proliferative retinal angiogenesis may severely impair the retina. Previous studies have indicated that matrix metalloproteinase (MMP)-2 and MMP-9 play important roles in the process of retinal angiogenesis. In this study, we suppressed MMP-2 and MMP-9 expression with RNA interference (RNAi) and then observed the inhibitory effects on the invasion and migration of human retinal microvascular endothelial cells (HRMECs).

METHODS

Small interfering RNAs against MMP-2 mRNA and MMP-9 mRNA were synthesized. After transfection, the MMP-2 and MMP-9 expression in HRMECs was examined by real-time polymerase chain reaction and Western blot analysis. Cell migration and invasion were measured with a migration assay and a scratch wound assay, respectively.

RESULTS

RNAi against MMP-2 and MMP-9 successfully inhibited the mRNA and protein expression of MMP-2 and MMP-9 in HRMECs. MMP-2 and MMP-9 knockdown could inhibit the invasion and migration of HRMECs.

CONCLUSIONS

These findings suggest that the RNAi approach towards MMP-2 and MMP-9 may be a potentially effective therapeutic method for the treatment of proliferative retinal angiogenesis.

Effects of the ninein-like protein centrosomal protein on breast cancer cell invasion and migration

To investigate the effects of the centrosomal protein, ninein-like protein (Nlp), on the proliferation, invasion and metastasis of MCF-7 breast cancer cells, the present study established green fluorescent protein (GFP)-containing MCF7 plasmids with steady and overexpression of Nlp (MCG7-GFP-N1p) and blank plasmids (MCF7-GFP) using lentiviral transfection technology in MCF7 the breast cancer cell line. The expression of Nlp was determined by reverse transcription-quantitative polymerase chain reaction and western blott analysis. Differences in levels of proliferation, invasion and metastasis between the MCF7-GFP-Nlp group and MCF-GFP group were compared using MTT, plate colony formation and Transwell migration assays. The cell growth was more rapid and the colony forming rate was markedly increased in the MCF7-GFP-Nlp group (P<0.05) compared with the MCF7-GFP group. The number of cells in the MCF-GFP-Nlp and MCF7-GFP groups transferred across membranes were 878±18.22 and 398±8.02, respectively, in the migration assay. The invasive capacity was significantly increased in the MCF7-GFP-Nlp group (P<0.05) compared with the MCF7-GFP group. The western blotting results demonstrated high expression levels of C-X-C chemokine receptor type 4 in the MCF7-GFP-Nlp group. The increased expression of Nlp was associated with an increase in MCF7 cell proliferation, invasion and metastasis, which indicated that Nlp promoted breast tumorigenesis and may be used as a potent biological index to predict breast cancer metastasis and develop therapeutic regimes.

Biodegradable nanoparticle-mediated K-ras down regulation for pancreatic cancer gene therapy

Biodegradable nanoparticle-mediated K-ras siRNA delivery has shown inhibition of cell proliferation, migration and invasion in pancreatic cancer cells.

Activation of glucagon-like peptide-1 receptor inhibits tumourigenicity and metastasis of human pancreatic cancer cells via PI3K/Akt pathway

AIMS

It has been reported that glucagon-like peptide-1 (GLP-1) agents are associated with an increased risk of pancreatic cancer in patients with type 2 diabetes. Reports have indicated that GLP-1 promotes pancreatic metaplasia and premalignant lesions. The aims of this study were to determine the effects of GLP-1-based therapy on pancreatic cancer cells.

METHODS

Immunohistochemistry was used to investigate GLP-1 receptor (GLP-1R) expression in 30 human pancreatic cancer tissues. We also analysed associated clinicopathological data and each patient's prognosis. Two human pancreatic cancer cell lines were used to evaluate the in vitro effects of the GLP-1R agonist liraglutide on cell growth, migration and invasion. Mouse xenograft models of human pancreatic cancer were established to evaluate the effects of liraglutide in vivo.

RESULTS

Human pancreatic cancer tissues showed lower levels or a lack of GLP-1R expression when compared with levels in the tumour-adjacent pancreatic tissues. Negative GLP-1R expression occurred more frequently in advanced tumours with larger diameters and lymphatic metastasis, and was associated with a poor prognosis. GLP-1R activation with liraglutide inhibited tumourigenicity and metastasis of human pancreatic cancer cells in vitro and in vivo. Akt activation was dose-dependently inhibited by liraglutide, and the PI3K inhibitors, LY294002 and wortmannin, displayed similar suppressive effects to liraglutide in human pancreatic cancer cells.

CONCLUSIONS

GLP-1R activation has an antitumour effect on human pancreatic cancers via inhibition of the PI3K/Akt pathway. This finding suggests that GLP-1-based therapies may be beneficial, rather than harmful, in treating type 2 diabetic patients with pancreatic cancer.

Extra virgin olive oil phenols suppress migration and invasion of T24 human bladder cancer cells through modulation of matrix metalloproteinase-2

The consumption of extra virgin olive oil (EVOO), a common dietary habit of the Mediterranean people, seems to be related to a lower incidence of certain types of cancer including bladder neoplasm. Metastases are the major cause of bladder cancer-related deaths and targeting cell motility has been proposed as a therapeutic strategy to prevent cancer spread. This study aimed to investigate the potential antimetastatic effect of total phenols extracted from EVOO against the human transitional bladder carcinoma cell line T24. We also aimed at verifying that EVOO extract exerts cytotoxic effect on tumor cells without affecting normal urothelial fibroblasts. Our results show that EVOO extract can significantly inhibit the proliferation and motility of T24 bladder cells in a dose-dependent manner. In the same experimental conditions fibroblast proliferation and motility were not significantly modified. Furthermore the enzymatic activity of MMP-2 was inhibited at nontoxic EVOO extract doses only in T24 cells. The qRT-PCR revealed a decrease of the MMP-2 expression and a simultaneous increase of the tissue inhibitors of metalloproteinases expression. Our results may support the epidemiological evidences that link olive oil consumption to health benefits and may represent a starting point for the development of new anticancer strategies.

Targeting the cancer-stroma interaction: a potential approach for pancreatic cancer treatment

Recent studies have demonstrated that the interaction between the cancer and the stroma, play a key role in the development of pancreatic cancer. The desmoplasia, which consists of fibroblasts, pancreatic stellate cells, lymphatic and vascular endothelial cells, immune cells, pathologic increased nerves, and the extracellular matrix (ECM), creates a complex tumor microenvironment that promotes pancreatic cancer development, invasion, metastasis, and resistance to chemotherapy. Thus, the potential approach for targeting the components of this desmoplastic reaction or the pancreatic tumor microenvironment might represent a novel therapeutic approach to advanced pancreatic carcinoma. Novel therapies that target on the pancreatic tumor microenvironment should become one of the more effective treatments for pancreatic cancer.

Deregulated signaling pathways in glioblastoma multiforme: molecular mechanisms and therapeutic targets

Glioblastoma multiforme (GBM) is the most malignant and aggressive type of brain tumor with an average life expectancy of less than 15 months. This is mostly due to the highly mutated genome of GBM, which is characterized by the deregulation of many key signaling pathways involving growth, proliferation, survival, and apoptosis. It is critical to explore novel diagnostic and therapeutic strategies that target these pathways to improve the treatment of malignant glioma in the future. This review summarizes the most common and important pathways that are highly mutated or deregulated in GBM and discusses potential therapeutic strategies targeting these pathways.

Effects of RNAi-mediated matrix metalloproteinase-2 gene silencing on the invasiveness and adhesion of esophageal carcinoma cells, KYSE150

BACKGROUND

Esophageal carcinoma is one of the main malignancies in China. Previous studies indicated that matrix metalloproteinases (MMPs) play important roles in the process of tumor invasion and metastasis in several types of solid tumors. Among all of the MMPs, MMP-2 is one of the MMPs closely associated with tumor invasion. In this study, we suppressed MMP-2 expression with RNA interference and then observed inhibitory effects on the invasion and migration of the esophageal carcinoma cell line KYSE150.

METHODS

Three target sequences were selected and siRNA against MMP-2 mRNA were synthesized. After being transfected by the transfection complexes, the MMP-2 expression of KYSE150 cells, which overexpresses MMP-2, were examined by Western blot analysis and real-time polymerase chain reaction (PCR). Cell migration and invasion were measured with migration assay and Boyden chamber assays, respectively.

RESULTS

RNAi against MMP-2 successfully inhibited the mRNA and protein expression of MMP-2 in the esophageal carcinoma cell line KYSE150. MMP-2 knockdown inhibited the invasion and migration of esophageal carcinoma cell line KYSE150.

CONCLUSIONS

These findings suggested that the RNAi approach towards MMP-2 may be a potentially effective therapeutic method for the treatment of esophageal carcinoma.

Perineural invasion and associated pain in pancreatic cancer

Perineural invasion (PNI) is a prominent characteristic of pancreatic cancer. PNI is a process whereby cancer cells invade the surrounding nerves, thus providing an alternative route for metastatic spread and pain generation. PNI is thought to be an indicator of aggressive tumour behaviour and has been shown to correlate with poor prognosis of patients with pancreatic cancer. Recent studies demonstrated that some signalling molecules and pathways that are involved in PNI are also involved in pain generation. Targeting these signalling pathways has shown some promise in alleviating pain and reducing PNI, which could potentially improve treatment outcomes for patients with pancreatic cancer.

ALCAM is associated with chemoresistance and tumor cell adhesion in pancreatic cancer

AIMS

Cell-cell adhesion is a major factor in integrity of epithelia which is frequently disturbed in cancer leading to local invasion and distant metastasis.

METHODS

To define expression and function of activated leukocyte cell adhesion molecule (ALCAM, CD166) in pancreatic cancer and in pancreatic neuroendocrine tumors (PNET), microarray analyses, RT-PCR, immunohistochemistry, RNAi, adhesion, migration, invasion, and chemoresistance assays were used.

RESULTS

We demonstrate that expression of ALCAM is altered and its serum levels are increased in pancreatic ductal adenocarcinoma (PDAC). ALCAM was expressed on the membranes of islet cells in the normal pancreas whereas normal pancreatic ducts were ALCAM-negative. In PDAC, ALCAM expression was generally rare though in some tumors, membranous, or cytoplasmic ALCAM was found. PNET were mostly ALCAM-positive with a cytoplasmic staining pattern which was in contrast to the membrane expression observed in non-transformed islet cells. In vitro, ALCAM silencing using RNAi had no effects on growth or invasion of pancreatic cancer cells but reduced cell adhesion and induced chemoresistance. In neuroendocrine tumor cell lines, silencing of ALCAM decreased cell growth.

CONCLUSIONS

We propose ALCAM as a novel serum biomarker in human pancreatic tumors which is associated with cell adhesion, growth and chemoresistance.

Targeted drug delivery in pancreatic cancer

Effective drug delivery in pancreatic cancer treatment remains a major challenge. Because of the high resistance to chemo and radiation therapy, the overall survival rate for pancreatic cancer is extremely low. Recent advances in drug delivery systems hold great promise for improving cancer therapy. Using liposomes, nanoparticles, and carbon nanotubes to deliver cancer drugs and other therapeutic agents such as siRNA, suicide gene, oncolytic virus, small molecule inhibitor, and antibody has been a success in recent preclinical trials. However, how to improve the specificity and stability of the delivered drug using ligand or antibody directed delivery represent a major problem. Therefore, developing novel, specific, tumor-targeted drug delivery systems is urgently needed for this terrible disease. This review summarizes the current progress on targeted drug delivery in pancreatic cancer and provides important information on potential therapeutic targets for pancreatic cancer treatment.