Anatomic and Surgical Aspects of Total Pancreatectomy in Swine.

BACKGROUND: The swine is a valuable model for preclinical research and surgical technique training. Induction of Type I diabetes is achieved by total pancreatectomy, therefore these animals may be used in several research studies, including islet transplantation field. Given the lack of information in the literature, the purpose of this work is to describe anatomic aspects of swine pancreas, the total pancreatectomy surgical technique, intra- and postoperative complications and the autopsy results. MATERIAL AND METHODS: Five hybrid male pigs, 20-35 kg, submitted to total pancreatectomy with duodenum, bile duct, and spleen preservation. Postoperatively, daily clinical assessment and capillary blood glucose collection were performed. At the end of the 30-day period or in the occurrence of serious clinical complications, euthanasia and autopsy were performed. RESULTS: The average duration of surgery was 128 minutes, without intraoperative deaths or anesthesia induction failures. The median survival was 6.6 days. Postoperative complications were weight loss (3), emesis (2), constipation (2), abdominal distension (2), diarrhea (1), and loss of appetite (1). All animals were euthanized due to serious complications. Two animals presented surgical complications (duodenal necrosis with gastroparesis and internal hernia with intestinal necrosis). The other 3 animals presented serious clinical complications related to exocrine pancreatic insufficiency due to deficiency of pancreatic enzymes. Glycemic values above 200 mg/dL were found on the first postoperative day and above 300 mg/dL on the seventh day in all animals. CONCLUSION: A model of total pancreatectomy with duodenum, spleen, and bile duct preservation in pigs was established. All animals became diabetic, however, animals without postoperative complications were euthanized due to serious complications related to pancreas exocrine insufficiency.

Recombinant Human Peptide Growth Factors, Bone Morphogenetic Protein-7 (rhBMP7), and Platelet-Derived Growth Factor-BB (rhPDGF-BB) for Osteoporosis Treatment in an Oophorectomized Rat Model.

Bone morphogenetic protein (BMP) and platelet-derived growth factor (PDGF) are known to regulate/stimulate osteogenesis, playing vital roles in bone homeostasis, rendering them strong candidates for osteoporosis treatment. We evaluated the effects of recombinant human BMP-7 (rhBMP7) and PDGF-BB (rhPDGF-BB) in an oophorectomy-induced osteoporosis rat model. Forty Sprague Dawley rats underwent oophorectomy surgery; treatments commenced on the 100th day post-surgery when all animals exhibited signs of osteoporosis. These peptide growth factors were administered intraocularly (iv) once or twice a week and the animals were monitored for a total of five weeks. Two weeks after the conclusion of the treatments, the animals were euthanized and tissues were collected for assessment of alkaline phosphatase, X-ray, micro-CT, and histology. The results indicate that the most promising treatments were 20 µg/kg rhPDGF-BB + 30 µg/kg rhBMP-7 twice a week and 30 µg/kg BMP-7 twice a week, showing significant increases of 15% (p < 0.05) and 13% (p < 0.05) in bone volume fraction and 21% (p < 0.05) and 23% (p < 0.05) in trabecular number, respectively. In conclusion, rhPDGF-BB and rhBMP-7 have demonstrated the ability to increase bone volume and density in this osteoporotic animal model, establishing them as potential candidates for osteoporosis treatment.

Islet transplantation: overcoming the organ shortage.

BACKGROUND: Type 1 diabetes mellitus (T1D) is a condition resulting from autoimmune destruction of pancreatic ß cells, leading patients to require lifelong insulin therapy, which, most often, does not avoid the most common complications of this disease. Transplantation of isolated pancreatic islets from heart-beating organ donors is a promising alternative treatment for T1D, however, this approach is severely limited by the shortage of pancreata maintained under adequate conditions. METHODS: In order to analyze whether and how this problem could be overcome, we undertook a retrospective study from January 2007 to January 2010, evaluating the profile of brain-dead human pancreas donors offered to our Cell and Molecular Therapy NUCEL Center ( www.usp.br/nucel ) and the basis for organ refusal. RESULTS: During this time period, 558 pancreata were offered by the São Paulo State Transplantation Central, 512 of which were refused and 46 were accepted for islet isolation and transplantation. Due to the elevated number of refused organs, we decided to analyze the main reasons for refusal in order to evaluate the possibility of improving the organ acceptance rate. The data indicate that hyperglycemia, technical issues, age, positive serology and hyperamylasemia are the top five main causes for declination of a pancreas offer. CONCLUSIONS: This study underlines the main reasons to decline a pancreas offer in Sao Paulo-Brazil and provides some guidance to ameliorate the rate of eligible pancreas donors, aiming at improving the islet isolation and transplantation outcome. TRIAL REGISTRATION: Protocol CAPPesq number 0742/02/CONEP 9230.

The Influence of rhBMP-7 Associated with Nanometric Hydroxyapatite Coatings Titanium Implant on the Osseointegration: A Pre-Clinical Study.

Background: Bioceramic nanometer coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings, and the association with bone morphogenetic protein (BMP) is an attempt to achieve faster osseointegration to hasten oral rehabilitation. Objective: This study aimed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osseointegration of titanium implants coated with a thin film surface of hydroxyapatite (HA). Methods: Two implants (n = 24) were placed in each white New Zealand rabbits' femur (n = 6). Implants were placed in the right femur after standard instrumentation (A and B) and in the left femur after an over-instrumentation (C and D), preventing bone-implant contact. The distal implants were installed associated with rhBMP-7 (groups B [regular instrumentation] and D [over-instrumentation]) and, also, in the absence of without BMP (control groups A [regular instrumentation] and C [over-instrumentation]). After 4 weeks, the animals were euthanized. The bone blocks containing the implants were embedded in methyl methacrylate and sectioned parallel to the long axis of the implant, which were analyzed by image segmentation. The data were analyzed using a nonparametric statistical method. Results: We observed that Group A had a mean bone formation of 35.6% compared to Group B, which had 48.6% (p > 0.05). Moreover, this group showed 28.3% of connective tissue compared to Group A, with 39.3%. In the over-instrumented groups, rhBMP-7 (Group D) showed an enhanced and significant increase in bone formation when compared with the group without rhBMP-7 (Group C). Conclusion: We concluded that the association of rhBMP-7 to thin nanostructure HA-coated implants promoted greater new bone area than the same implants in the absence of rhBMP-7, mainly in cases of over-instrumented implant sites.

Stem cells differentiation into insulin-producing cells (IPCs): recent advances and current challenges.

Type 1 diabetes mellitus (T1D) is a chronic disease characterized by an autoimmune destruction of insulin-producing ß-pancreatic cells. Although many advances have been achieved in T1D treatment, current therapy strategies are often unable to maintain perfect control of glycemic levels. Several studies are searching for new and improved methodologies for expansion of ß-cell cultures in vitro to increase the supply of these cells for pancreatic islets replacement therapy. A promising approach consists of differentiation of stem cells into insulin-producing cells (IPCs) in sufficient number and functional status to be transplanted. Differentiation protocols have been designed using consecutive cytokines or signaling modulator treatments, at specific dosages, to activate or inhibit the main signaling pathways that control the differentiation of induced pluripotent stem cells (iPSCs) into pancreatic ß-cells. Here, we provide an overview of the current approaches and achievements in obtaining stem cell-derived ß-cells and the numerous challenges, which still need to be overcome to achieve this goal. Clinical translation of stem cells-derived ß-cells for efficient maintenance of long-term euglycemia remains a major issue. Therefore, research efforts have been directed to the final steps of in vitro differentiation, aiming at production of functional and mature ß-cells and integration of interdisciplinary fields to generate efficient cell therapy strategies capable of reversing the clinical outcome of T1D.

Role of MSC-derived small extracellular vesicles in tissue repair and regeneration.

Mesenchymal stem cells (MSCs) are crucial for tissue homeostasis and repair, secreting vesicles to the extracellular environment. Isolated exosomes were shown to affect angiogenesis, immunomodulation and tissue regeneration. Numerous efforts have been dedicated to describe the mechanism of action of these extracellular vesicles (EVs) and guarantee their safety, since the final aim is their therapeutic application in the clinic. The major advantage of applying MSC-derived EVs is their low or inexistent immunogenicity, prompting their use as drug delivery or therapeutic agents, as well as wound healing, different cancer types, and inflammatory processes in the neurological and cardiovascular systems. MSC-derived EVs display no vascular obstruction effects or apparent adverse effects. Their nano-size ensures their passage through the blood-brain barrier, demonstrating no cytotoxic or immunogenic effects. Several in vitro tests have been conducted with EVs obtained from different sources to understand their biology, molecular content, signaling pathways, and mechanisms of action. Application of EVs to human therapies has recently become a reality, with clinical trials being conducted to treat Alzheimer's disease, retina degeneration, and COVID-19 patients. Herein, we describe and compare the different extracellular vesicles isolation methods and therapeutic applications regarding the tissue repair and regeneration process, presenting the latest clinical trial reports.

Kidney organoids generated from erythroid progenitors cells of patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Kidney organoids have been broadly obtained from commercially available induced pluripotent stem cells (iPSCs); however, it has been a great challenge to efficiently produce renal organoid models from patients with autosomal dominant polycystic kidney disease (ADPKD) that recapitulate both embryogenesis and the mechanisms of cystogenesis. METHODS: Blood erythroid progenitors (EPs) from two ADPKD patients and one healthy donor (HC) was used as a comparative control to normalize the many technical steps for reprogramming EPs and for the organoids generation. EPs were reprogrammed by an episomal vector into iPSCs, which were differentiated into renal tubular organoids and then stimulated by forskolin to induce cysts formation. RESULTS: iPSCs derived from EPs exhibited all characteristics of pluripotency and were able to differentiate into all three germ layers. 3D tubular organoids were generated from single cells after 28 days in Matrigel. HC and ADPKD organoids did not spontaneously form cysts, but upon forskolin stimulation, cysts-like structures were observed in the ADPKD organoids but not in the HC-derived organoids. CONCLUSION: The findings of this study showed that kidney organoids were successfully generated from the blood EP cells of ADPKD patients and a healthy control donor. This approach should contribute as a powerful tool for embryonic kidney development model, which is able to recapitulate the very early pathophysiological mechanisms involved in cytogenesis.

Low RECK Expression Is Part of the Cervical Carcinogenesis Mechanisms.

Human papillomavirus (HPV)-induced carcinogenesis comprises alterations in the expression and activity of matrix metalloproteinases (MMP) and their regulators. Reversion-inducing Cysteine-rich protein with Kazal motifs (RECK) inhibits the activation of specific metalloproteinases and its expression is frequently lost in human cancers. Here we analyzed the role of RECK in cervical carcinogenesis. Cervical cancer derived cell lines over expressing RECK were used to determine tumor kinetics as well as, cellular, immune and molecular properties in vivo. Besides, we analyzed RECK expression in cervical cancer samples. RECK over expression (RECK+) delayed tumor growth and increased overall survival in vivo. RECK+ tumors displayed an increase in lymphoid-like inflammatory infiltrating cells, reduced number and viability of tumor and endothelial cells and lower collagenase activity. RECK+ tumors exhibited an enrichment of cell adhesion processes both in the mouse model and cervical cancer clinical samples. Finally, we found that lower RECK mRNA levels were associated with cervical lesions progression and worse response to chemotherapy in cervical cancer patients. Altogether, we show that increased RECK expression reduced the tumorigenic potential of HPV-transformed cells both in vitro and in vivo, and that RECK down regulation is a consistent and clinically relevant event in the natural history of cervical cancer.

Characterization of rat liver bud-derived cells.

Cells derived from the fetal liver have been shown to be a rich source of progenitor stem cells, constituting a promising source for Tissue Engineering and Regenerative Medicine. In this study, embryo and fetal liver-bud derived cells from Fischer 344 rats were obtained at E12.5, E14.5 and E16.5 gestational days and evaluated for cell phenotype, survival and proliferation. Liver transaminase (AST and ALT) and AFP levels were lower in embryo liver-bud-derived cells on day 12.5. Markers for stem cells, cell cycle progression and cell death were differentially expressed in E12.5 cell cultures. Analysis of mitochondrial electric potential on 14.5 and 16.5 days showed a tendency for cells with lower functional or metabolic ability, in comparison to cultures derived from day 12.5. The results demonstrated that the majority of the E16.5 cells were in the G0 / G1 phase. The capacity of synthesis (S) and cellular division (G2 / M) of embryo and fetal liver bud-derived cells was constant over all gestational periods. In conclusion, embryo and fetal liver-bud-derived cells during the periods of 12.5 and 14.5 days, showed expression profile of progenitor cells, cell activity and hematopoietic function in culture.

R-Spondin1 enhances wnt signaling and decreases weight loss in short bowel syndrome zebrafish.

BACKGROUND: R-spondins, including R-spondin 1 (RSPO1), are a family of Wnt ligands that help to activate the canonical Wnt/ß-catenin pathway, which is critical for intestinal epithelial cell proliferation and maintenance of intestinal stem cells. This proliferation underpins the epithelial expansion, or intestinal adaptation (IA), that occurs following massive bowel resection and short bowel syndrome (SBS). The purpose of this study was to identify if recombinant human RSPO1 (rhRSPO1) could be serially administered to SBS zebrafish to enhance cellular proliferation and IA. METHODS: Adult male zebrafish were assigned to four groups: sham + PBS, SBS + PBS, sham + rhRSPO1, and SBS + rhRSPO1. Sham fish had a laparotomy alone. SBS fish had a laparotomy with distal intestinal ligation and creation of a proximal stoma. Fish were weighed at initial surgery and then weekly. rhRSPO1 was administered post-operatively following either a one- or two-week dosing schedule with either 3 or 5 intraperitoneal injections, respectively. Fish were harvested at 7 or 14 days with intestinal segments collected for analysis. RESULTS: Repeated intraperitoneal injection of rhRSPO1 was feasible and well tolerated. At 7 days, intestinal epithelial proliferation was increased by rhRSPO1. At 14 days, SBS + rhRSPO1 fish lost significantly less weight than SBS + PBS fish. Measurements of intestinal surface area were not increased by rhRSPO1 administration but immunofluorescent staining for ß-catenin and gene expression for cyclin D1 was increased. CONCLUSIONS: Intraperitoneal injection of rhRSPO1 decreased weight loss in SBS zebrafish with increased ß-catenin + cells and cyclin D1 expression at 14 days, indicating improved weight maintenance might result from increased activation of the canonical Wnt pathway.

Therapeutic potential of human induced pluripotent stem cells and renal progenitor cells in experimental chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a global public health problem. Cell therapy using pluripotent stem cells represents an attractive therapeutic approach for the treatment of CKD. METHODS: We transplanted mitomycin C (MMC)-treated human induced pluripotent stem cells (hiPSCs) and renal progenitor cells (RPCs) into a CKD rat model system. The RPC and hiPSC cells were characterized by immunofluorescence and qRT-PCR. Untreated 5/6 nephrectomized rats were compared to CKD animals receiving the same amount of MMC-treated hiPSCs or RPCs. Renal function, histology, and immunohistochemistry were evaluated 45 days post-surgery. RESULTS: We successfully generated hiPSCs from peripheral blood and differentiated them into RPCs expressing renal progenitor genes (PAX2, WT1, SIX2, and SALL1) and podocyte-related genes (SYNPO, NPHS1). RPCs also exhibited reduced OCT4 expression, confirming the loss of pluripotency. After cell transplantation into CKD rats, the body weight change was significantly increased in both hiPSC and RPC groups, in comparison with the control group. Creatinine clearance (CCr) was preserved only in the hiPSC group. Similarly, the number of macrophages in the kidneys of the hiPSC group reached a statistically significant reduction, when compared to control rats. Both treatments reduced positive staining for the marker α-smooth muscle actin. Histological features showed decreased tubulointerstitial damage (interstitial fibrosis and tubular atrophy) as well as a reduction in glomerulosclerosis in both iPSC and RPC groups. CONCLUSIONS: In conclusion, we describe that both MMC-treated hiPSCs and RPCs exert beneficial effects in attenuating CKD progression. Both cell types were equally efficient to reduce histological damage and weight loss caused by CKD. hiPSCs seem to be more efficient than RPCs, possibly due to a paracrine effect triggered by hiPSCs. These results demonstrate that the use of MMC-treated hiPSCs and RPCs improves clinical and histological CKD parameters, avoided tumor formation, and therefore may be a promising cell therapy strategy for CKD.

R-Spondin 1 (RSPO1) Increases Mouse Intestinal Organoid Unit Size and Survival in vitro and Improves Tissue-Engineered Small Intestine Formation in vivo.

Introduction: Cell therapy and tissue engineering has recently emerged as a new option for short bowel syndrome (SBS) treatment, generating tissue engineered small intestine (TESI) from organoid units (OU) and biodegradable scaffolds. The recombinant human R-Spondin 1 (rhRSPO1) protein may be a key player in this process due to its mitogenic activity in intestinal stem cells. Objective: Aiming at optimizing the TESI formation process and advancing this technology closer to the clinic, we evaluated the effects of rhRSPO1 protein on OU culture and TESI formation. Methods: Intestinal OU were isolated from C57BL/6 mice and cultured in Matrigel in the presence or absence of recombinant human rhRSPO1. Throughout the culture, OU growth and survival rates were evaluated, and cells were harvested on day 3. OU were seeded onto biodegradable scaffolds, in the presence or absence of 5 µg of rhRSPO1 and implanted into the omentum of NOD/SCID mice in order to generate TESI. The explants were harvested after 30 days, weighed, fixed in formalin and embedded in paraffin for histological analysis and immunofluorescence for different cell markers. Results: After 3 days, rhRSPO1-treated OU attained a larger size, when compared to the control group, becoming 5.7 times larger on day 6. Increased survival was observed from the second day in culture, with a 2-fold increase in OU survival between days 3 and 6. A 4.8-fold increase of non-phosphorylated ß-catenin and increased relative expression of Lgr5 mRNA in the rhRSPO1-treated group confirms activation of the canonical Wnt pathway and suggests maintenance of the OU stem cell niche and associated stemness. After 30 days of in vivo maturation, rhRSPO1-treated TESI presented a larger mass than constructs treated with saline, developing a more mature intestinal epithelium with well-formed villi and crypts. In addition, the efficiency of OU-loaded rhRSPO1-treated scaffolds significantly increased, forming TESI in 100% of the samples (N = 8), of which 40% presented maximum degree of development, as compared to 66.6% in the control group (N = 9). Conclusion: rhRSPO1 treatment improves the culture of mouse intestinal OU, increasing its size and survival in vitro, and TESI formation in vivo, increasing its mass, degree of development and engraftment.

Emerging Roles and Potential Applications of Non-Coding RNAs in Glioblastoma.

Non-coding RNAs (ncRNAs) comprise a diversity of RNA species, which do not have the potential to encode proteins. Non-coding RNAs include two classes of RNAs, namely: short regulatory ncRNAs and long non-coding RNAs (lncRNAs). The short regulatory RNAs, containing up to 200 nucleotides, include small RNAs, such as microRNAs (miRNA), short interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs), and small nucleolar RNAs (snoRNAs). The lncRNAs include long antisense RNAs and long intergenic RNAs (lincRNAs). Non-coding RNAs have been implicated as master regulators of several biological processes, their expression being strictly regulated under physiological conditions. In recent years, particularly in the last decade, substantial effort has been made to investigate the function of ncRNAs in several human diseases, including cancer. Glioblastoma is the most common and aggressive type of brain cancer in adults, with deregulated expression of small and long ncRNAs having been implicated in onset, progression, invasiveness, and recurrence of this tumor. The aim of this review is to guide the reader through important aspects of miRNA and lncRNA biology, focusing on the molecular mechanism associated with the progression of this highly malignant cancer type.

Fluorescence-based method is more accurate than counting-based methods for plotting growth curves of adherent cells.

OBJECTIVE: Cell growth curves constitute one of the primary assays employed to analyze cell proliferation dynamics of in vitro cultured cells under specific culture conditions. From the cell growth curve, it is possible to assess the behavior of proliferating cells under different conditions, such as drug treatment and genomic editions. Traditionally, growth curves for adherent cells are obtained by seeding the cells in multiple-well plates and counting the total number of cells at different time points. Here, we compare this traditional method to the fluorescence-based method, which is based on the CFSE fluorescence decay over time. RESULTS: The fluorescence-based method is not dependent on the determination of the total number of cells, but rather is approached by assessing the fluorescence of a sample of single cells from a cell population at different time points after plating. Therefore, this method is not biased due to either cell loss during harvesting or to the presence of cellular debris and cell clumps. Moreover, the fluorescence-based method displays lower variation among different measurements of the same time point, which increases the reliability on the determination of lag, log and stationary phase transitions.

Production, purification and characterization of recombinant human R-spondin1 (RSPO1) protein stably expressed in human HEK293 cells.

BACKGROUND: The R-Spondin proteins comprise a family of secreted proteins, known for their important roles in cell proliferation, differentiation and death, by inducing the Wnt pathway. Several studies have demonstrated the importance of RSPOs in regulation of a number of tissue-specific processes, namely: bone formation, skeletal muscle tissue development, proliferation of pancreatic ß-cells and intestinal stem cells and even cancer. RSPO1 stands out among RSPOs molecules with respect to its potential therapeutic use, especially in the Regenerative Medicine field, due to its mitogenic activity in stem cells. Here, we generated a recombinant human RSPO1 (rhRSPO1) using the HEK293 cell line, obtaining a purified, characterized and biologically active protein product to be used in Cell Therapy. The hRSPO1 coding sequence was synthesized and subcloned into a mammalian cell expression vector. HEK293 cells were stably co-transfected with the recombinant expression vector containing the hRSPO1 coding sequence and a hygromycin resistance plasmid, selected for hygror and subjected to cell clones isolation. RESULTS: rhRSPO1 was obtained, in the absence of serum, from culture supernatants of transfected HEK293 cells and purified using a novel purification strategy, involving two sequential chromatographic steps, namely: heparin affinity chromatography, followed by a molecular exclusion chromatography, designed to yield a high purity product. The purified protein was characterized by Western blotting, mass spectrometry and in vitro (C2C12 cells) and in vivo (BALB/c mice) biological activity assays, confirming the structural integrity and biological efficacy of this human cell expression system. Furthermore, rhRSPO1 glycosylation analysis allowed us to describe, for the first time, the glycan composition of this oligosaccharide chain, confirming the presence of an N-glycosylation in residue Asn137 of the polypeptide chain, as previously described. In addition, this analysis revealing the presence of glycan structures such as terminal sialic acid, N-acetylglucosamine and/or galactose. CONCLUSION: Therefore, a stable platform for the production and purification of recombinant hRSPO1 from HEK293 cells was generated, leading to the production of a purified, fully characterized and biologically active protein product to be applied in Tissue Engineering.

Increased Mmp/Reck Expression Ratio Is Associated with Increased Recognition Memory Performance in a Parkinson's Disease Animal Model.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder worldwide. Among its non-motor symptoms, sleep disorders are extremely common, being linked to cognitive and memory disruption. The microenvironment, particularly the extracellular matrix (ECM), is deeply involved in memory consolidation as well as in neuropathological processes, such as inflammation, damage to the blood-brain barrier and neuronal death. To better understand ECM dynamics in PD memory disturbances, we investigated the orchestrated expression of Mmps (Mmp-3, Mmp-7, and Mmp-9) and their modulators (Reck and Timp-3) in a rotenone-induced PD model. Also, we introduced an additional intervention in the memory process through rapid eye movement sleep deprivation (REMSD). We observed a REMSD-induced trend in reversing the memory impairment caused by rotenone administration. Associated to this phenotype, we observed a significant increase in Mmp-7/Reck and Mmp-9/Reck mRNA expression ratio in the substantia nigra and Mmp-9/Reck ratio in the hypothalamus. Moreover, the positive correlation of Mmp/Reck expression ratios between the substantia nigra and the striatum, observed upon rotenone infusion, was reversed by REMSD. Taken together, our results suggest a potential orchestrated association between an increase in Mmp-7 and Mmp-9/Reck expression ratios in the substantia nigra and a possible positive effect on cognitive performance in subjects affected by PD.

The alternatively spliced RECK transcript variant 3 is a predictor of poor survival for melanoma patients being upregulated in aggressive cell lines and modulating MMP gene expression in vitro.

The reversion-inducing cysteine-rich protein with kazal motifs (RECK) gene was described as a tumor suppressor gene two decades ago. Recently, novel alternatively spliced products of this gene have been identified. Of these, the transcript variant 3 (RECKVar3) was shown to display tumor-facilitating effects in astrocytoma cells in vitro, with a higher RECKVar3/canonical RECK expression ratio being correlated with lower survival rates of patients. However, the regulatory mechanisms through which the cell controls the production and maintenance of these alternative transcripts, as well as their expression in other tumor types, remain elusive. Thus, the aim of this study is to investigate the role of the alternatively spliced transcripts from the RECK gene in melanoma progression as well as their regulation mechanism. To this end, we analyzed data from the Cancer Genome Atlas network and experimental data obtained from a panel of cell lines to show that high levels of RECKVar3 are predictive of poor survival. We also show that the MAPK and PI3K signaling pathways clearly play a role in determining the alternative-to-canonical ratio in vitro. Finally, we show that overexpression of the RECKVar3 protein upregulates matrix metalloproteinases (MMP)-9 and MMP-14 mRNA, while downregulating their inhibitor, tissue inhibitor of metalloproteinase (TIMP)3, and that RECKVar3-specific knockdown in the 1205Lu melanoma cell line hampered upregulation of the MMP9 mRNA promoted by the MEK1/2 inhibitor U0126. Taken together, our data complement the evidence that the RECK gene has a dual role in cancer, contributing to better understanding of the signaling cues, which dictate the melanoma invasive potential.

Functional impact of the long non-coding RNA MEG3 deletion by CRISPR/Cas9 in the human triple negative metastatic Hs578T cancer cell line.

Long non-coding RNAs (lncRNAs) serve critical roles in regulating cellular homeostasis, and their deregulated expression/activity is associated with neoplastic transformation. The maternally expressed gene 3 (MEG3) has been extensively described as a tumor suppressor gene in different types of cancer, including breast cancer. Interestingly, using a panel of seven different breast cancer cell lines, the present study revealed that MEG3 is highly expressed in the triple negative metastatic human Hs578T breast cancer cell line, which is refractory to different therapeutic approaches. Therefore, the present study aimed to investigate the phenotypic impact of MEG3 deletion in this cell line. Using the CRISPR/Cas9 system, complete knockout (KO) of MEG3 was achieved. Deletion was confirmed by genomic PCR and reverse transcription-quantitative PCR. The MEG3_KO cell population displaying the highest efficiency of genomic editing was selected for phenotypic in vitro assays, including wound scratch and Transwell assays, flow cytometry and immunofluorescence. The results demonstrated that MEG3 deletion increased cell proliferation, anchorage-independent cell growth and cell motility, which was consistent with its well-known tumor suppressor function. However, the present study revealed that MEG3_KO also lead to decreased cell invasiveness ability, supporting previous evidence that MEG3 modulates epithelial-to-mesenchymal inducing factors. The present study demonstrated that deletion of MEG3 promoted an increase in transforming growth factor ß and N-cadherin protein levels and significant reduction in matrix metallopeptidase 2, zinc-finger E-box binding homeobox 1 and collagen type III α1 chain gene expression levels. Additionally, MEG3_KO cells displayed significant resistance to doxorubicin treatment, demonstrating the role of this lncRNA in cancer cell survival by regulating apoptosis. The present study highlighted the utility of CRISPR/Cas9 for anticancer studies of intergenic lncRNAs and demonstrated that, although Hs578T cells express MEG3 at high levels, these cells display mechanisms to escape the growth suppression effects of this lncRNA. Notably, the detailed pathological mechanisms of MEG3 concerning tumor metastasis remain to be elucidated prior to applying MEG3 expression/activation in future therapeutic approaches for breast cancer treatment.