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1.
Eur J Gastroenterol Hepatol ; 36(5): 571-577, 2024 May 01.
Article En | MEDLINE | ID: mdl-38477855

BACKGROUND: Opioids are pain relievers that are often associated with opioid-induced constipation (OIC) that worsens with age. We performed a multicenter, retrospective analysis on the efficacy and safety of naldemedine, an opioid receptor antagonist, in treating OIC in patients with cancer (age >75 years). METHODS: The electronic medical records of cancer patients who received naldemedine at 10 Japanese institutions between 7 June 2017 and August 31, 2019, were retrieved. Patients aged ≥75 years who were treated with naldemedine for the first time and hospitalized for at least 7 days before and after initiating naldemedine therapy were included in this analysis. RESULTS: Sixty patients were observed for at least 7 days before and after starting naldemedine. The response rate was 68.3%, and the frequency of bowel movements increased significantly after naldemedine administration in the overall population ( P  < 0.0001) and among those who defecated <3 times/week before naldemedine administration ( P  < 0.0001). Diarrhea was the most frequent adverse event in all grades, observed in 45% of patients, of which 92.6% were Grade 1 or 2. Grade 4 or higher adverse events, including death, were not observed. CONCLUSION: Naldemedine exhibits significant efficacy and safety in OIC treatment in older patients with cancer.


Naltrexone/analogs & derivatives , Neoplasms , Opioid-Induced Constipation , Humans , Aged , Analgesics, Opioid/adverse effects , Retrospective Studies , Opioid-Induced Constipation/drug therapy , Constipation/chemically induced , Constipation/drug therapy , Neoplasms/complications , Neoplasms/drug therapy
2.
J Palliat Med ; 26(4): 548-553, 2023 04.
Article En | MEDLINE | ID: mdl-36971576

Background: Constipation is a concern among patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 3 and 4. Objectives: To assess naldemedine's efficacy and safety in cancer patients on opioids with poor PS. Design: Multicenter, retrospective study. Setting/Subjects: Japanese cancer patients with ECOG performance status 3 or 4 who received naldemedine. Measurements: Frequency of defecations before/after naldemedine use. Responders were patients whose defecation frequency increased to ≥3 times/week, from baseline ≥1 defecations/week over seven days after naldemedine administration. Results: Seventy-one patients were analyzed; 66.1% were responders (95% confidence interval: 54.5%-76.1%). Defecation frequency increased significantly after naldemedine in the overall population (6 vs. 2, p < 0.0001) and among those who defecated <3 times/week before naldemedine (4.5 vs. 1, p < 0.0001). Diarrhea (38.0%) of all grades was the most common adverse event; 23 (85.2%) events were classified as Grade 1 or 2. Conclusion: Naldemedine is effective and safe among cancer patients with poor PS.


Neoplasms , Opioid-Induced Constipation , Humans , Analgesics, Opioid/adverse effects , Narcotic Antagonists/therapeutic use , Opioid-Induced Constipation/drug therapy , Constipation/chemically induced , Constipation/drug therapy , Retrospective Studies , Naltrexone/therapeutic use , Neoplasms/complications , Neoplasms/drug therapy
3.
Medicina (Kaunas) ; 59(3)2023 Mar 02.
Article En | MEDLINE | ID: mdl-36984494

Background and Objectives: Opioid analgesics, which are used for cancer-related pain management, cause opioid-induced constipation (OIC). Naldemedine, a peripheral opioid receptor antagonist, is an OIC-modifying agent, but no focused efficacy and safety analysis has been conducted for its use in hepatobiliary pancreatic cancers. We performed a multi-institutional study on the efficacy and safety of naldemedine in patients with hepatobiliary pancreatic cancer using opioids in clinical practice. Materials and Methods: We retrospectively evaluated patients with hepatobiliary pancreatic cancer (including liver, biliary tract, and pancreatic cancers) treated with opioids and naldemedine during hospitalization at ten institutions in Japan from June 2017 to August 2019. We assessed the frequency of bowel movements before and after the initiation of naldemedine therapy. Responders were defined as patients who defecated ≥3 times/week, with an increase from a baseline of ≥1 defecations/week over seven days after the initiation of naldemedine administration. Results: Thirty-four patients were observed for one week before and one week after starting naldemedine. The frequency of bowel movements increased by one over the baseline frequency or to at least thrice per week in 21 patients. The response rate was 61.7% (95% confidence interval: 45.4-78.0%). The median number of weekly bowel movements before and after naldemedine treatment was 2 (range: 0-9) and 6 (range: 1-17), respectively, in the overall population (n = 34); the increase in the number of bowel movements following naldemedine administration was statistically significant (Wilcoxon signed-rank test, p < 0.0001). Diarrhea was the predominant gastrointestinal symptom, and 10 (29.4%) patients experienced grade 1, grade 2, or grade 3 adverse events. The only other adverse event included fatigue in one patient; grade 2-4 adverse events were absent. Conclusions: Naldemedine is effective, and its use may be safe in clinical practice for patients with hepatobiliary pancreatic cancer receiving opioid analgesics.


Narcotic Antagonists , Opioid-Induced Constipation , Pancreatic Neoplasms , Humans , Analgesics, Opioid/adverse effects , Narcotic Antagonists/therapeutic use , Opioid-Induced Constipation/drug therapy , Pancreatic Neoplasms/complications , Pancreatic Neoplasms/drug therapy , Retrospective Studies , Naltrexone/analogs & derivatives , Pancreatic Neoplasms
4.
Thorac Cancer ; 13(16): 2301-2308, 2022 08.
Article En | MEDLINE | ID: mdl-35790500

BACKGROUND: We conducted a multicenter, retrospective study on the efficacy and safety of naldemedine in thoracic cancer patients using opioids in clinical practice. METHODS: We retrospectively evaluated thoracic cancer patients treated with naldemedine at 10 institutions in Japan. Clinical data of patients administered naldemedine between June 2017 and August 2019 were extracted from electronic medical records. Inclusion criteria were as follows: (i) patients hospitalized for at least seven days before and after naldemedine administration, and (ii) those whose frequency of defecation was entered in the medical records. RESULTS: Forty patients were analyzed, and defecation frequency was observed for at least seven days before and after naldemedine administration. The response rate was 65.0% (95% CI: 50.2%-79.7%). The number of defecations increased significantly after naldemedine administration in the overall population, as well as among only those who defecated <3 times/week before naldemedine administration, and those that were administered ≥30 mg/day of morphine equivalent. Diarrhea was the most common adverse event in all grades, occurring in 11 patients (27.5%), of which 9 (81.8%) were grade 1 or 2. None of the patients experienced grade 4 or higher adverse events. CONCLUSION: The efficacy and safety of naldemedine for thoracic cancer patients in clinical practice were comparable with those of prospective studies, which suggest that naldemedine may be effective and feasible for most thoracic cancer patients.


Opioid-Induced Constipation , Thoracic Neoplasms , Analgesics, Opioid/adverse effects , Constipation/chemically induced , Constipation/drug therapy , Humans , Naltrexone/analogs & derivatives , Narcotic Antagonists/adverse effects , Prospective Studies , Retrospective Studies , Thoracic Neoplasms/drug therapy
5.
Yakugaku Zasshi ; 142(8): 893-900, 2022.
Article Ja | MEDLINE | ID: mdl-35908950

"Leukerin® powder 10%" containing mercaptopurine (6-MP) is an oral anticancer drug that requires careful handling. As a powder formulation, there are risks of exposure due to scattering during dispensing and possible 6-MP contamination to other drugs due to adhesion to the packaging machine. We previously reported that wiping with an alcohol-containing towel is useful for removing scattered powder after dispensing. However, it is recommended to wipe disk-type powder-packaging machines with water instead of cleaning with the alcohol-containing towel. Hence, we scattered 6-MP powder 100 mg (total amount of 6-MP: 10 mg), and then wiped with water three times using different types of cloth each time. We confirmed that third time wiping cloth did not have any 6-MP. Furthermore, we confirmed that the adhering 6-MP could be removed by wipe-cleaning (water-wiping twice and dry-wiping once) after dispensing 6-MP powder at two pharmacies that routinely dispensed 6-MP powder using a disk-type powder-packaging machine. In addition, we confirmed the adhesion of 6-MP in parts of the machine not cleaned by wipe-cleaning and also in parts that were washed only with water, in both the pharmacies. Based on the above observations, we recommend the following steps for cleaning disk-type powder-packaging machines after dispensing 6-MP powder: (1) wipe-cleaning that includes water-wiping twice and then dry-wiping once, (2) cleaning all areas of the packaging machine, and (3) wipe-cleaning with water before washing with water.


Pharmacies , Drug Packaging , Humans , Mercaptopurine , Powders , Water
6.
Nature ; 592(7852): 99-104, 2021 04.
Article En | MEDLINE | ID: mdl-33627870

The small intestine is the main organ for nutrient absorption, and its extensive resection leads to malabsorption and wasting conditions referred to as short bowel syndrome (SBS). Organoid technology enables an efficient expansion of intestinal epithelium tissue in vitro1, but reconstruction of the whole small intestine, including the complex lymphovascular system, has remained challenging2. Here we generate a functional small intestinalized colon (SIC) by replacing the native colonic epithelium with ileum-derived organoids. We first find that xenotransplanted human ileum organoids maintain their regional identity and form nascent villus structures in the mouse colon. In vitro culture of an organoid monolayer further reveals an essential role for luminal mechanistic flow in the formation of villi. We then develop a rat SIC model by repositioning the SIC at the ileocaecal junction, where the epithelium is exposed to a constant luminal stream of intestinal juice. This anatomical relocation provides the SIC with organ structures of the small intestine, including intact vasculature and innervation, villous structures, and the lacteal (a fat-absorbing lymphatic structure specific to the small intestine). The SIC has absorptive functions and markedly ameliorates intestinal failure in a rat model of SBS, whereas transplantation of colon organoids instead of ileum organoids invariably leads to mortality. These data provide a proof of principle for the use of intestinal organoids for regenerative purposes, and offer a feasible strategy for SBS treatment.


Colon/cytology , Ileum/transplantation , Intestinal Mucosa/cytology , Organoids/transplantation , Regeneration , Regenerative Medicine/methods , Short Bowel Syndrome/therapy , Animals , Colon/blood supply , Colon/innervation , Colon/surgery , Disease Models, Animal , Heterografts , Humans , Ileum/cytology , Intestinal Mucosa/blood supply , Intestinal Mucosa/innervation , Intestinal Mucosa/surgery , Male , Organ Culture Techniques , Organoids/cytology , Rats , Rats, Inbred Lew , Short Bowel Syndrome/pathology , Short Bowel Syndrome/surgery
7.
Cancer Res ; 80(23): 5355-5366, 2020 12 01.
Article En | MEDLINE | ID: mdl-33077554

Drug-induced resistance, or tolerance, is an emerging yet poorly understood failure of anticancer therapy. The interplay between drug-tolerant cancer cells and innate immunity within the tumor, the consequence on tumor growth, and therapeutic strategies to address these challenges remain undescribed. Here, we elucidate the role of taxane-induced resistance on natural killer (NK) cell tumor immunity in triple-negative breast cancer (TNBC) and the design of spatiotemporally controlled nanomedicines, which boost therapeutic efficacy and invigorate "disabled" NK cells. Drug tolerance limited NK cell immune surveillance via drug-induced depletion of the NK-activating ligand receptor axis, NK group 2 member D, and MHC class I polypeptide-related sequence A, B. Systems biology supported by empirical evidence revealed the heat shock protein 90 (Hsp90) simultaneously controls immune surveillance and persistence of drug-treated tumor cells. On the basis of this evidence, we engineered a "chimeric" nanotherapeutic tool comprising taxanes and a cholesterol-tethered Hsp90 inhibitor, radicicol, which targets the tumor, reduces tolerance, and optimally reprimes NK cells via prolonged induction of NK-activating ligand receptors via temporal control of drug release in vitro and in vivo. A human ex vivo TNBC model confirmed the importance of NK cells in drug-induced death under pressure of clinically approved agents. These findings highlight a convergence between drug-induced resistance, the tumor immune contexture, and engineered approaches that consider the tumor and microenvironment to improve the success of combinatorial therapy. SIGNIFICANCE: This study uncovers a molecular mechanism linking drug-induced resistance and tumor immunity and provides novel engineered solutions that target these mechanisms in the tumor and improve immunity, thus mitigating off-target effects.


Antineoplastic Agents, Immunological/pharmacology , Breast Neoplasms/drug therapy , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Killer Cells, Natural/drug effects , Animals , Antineoplastic Agents, Immunological/chemistry , Breast Neoplasms/immunology , Breast Neoplasms/pathology , Cell Line, Tumor , Cholesterol/chemistry , Docetaxel/administration & dosage , Docetaxel/pharmacokinetics , Drug Delivery Systems , Drug Liberation , Drug Resistance, Neoplasm , Female , HSP90 Heat-Shock Proteins/metabolism , Humans , Killer Cells, Natural/immunology , Macrolides/chemistry , Macrolides/pharmacokinetics , Macrolides/pharmacology , Mice, Inbred BALB C , Molecular Targeted Therapy/methods , Nanoparticles/chemistry , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/immunology , Triple Negative Breast Neoplasms/surgery , Tumor Microenvironment/drug effects , Tumor Microenvironment/immunology
8.
PLoS Comput Biol ; 15(8): e1007278, 2019 08.
Article En | MEDLINE | ID: mdl-31449515

Understanding intrinsic and acquired resistance is crucial to overcoming cancer chemotherapy failure. While it is well-established that intratumor, subclonal genetic and phenotypic heterogeneity significantly contribute to resistance, it is not fully understood how tumor sub-clones interact with each other to withstand therapy pressure. Here, we report a previously unrecognized behavior in heterogeneous tumors: cooperative adaptation to therapy (CAT), in which cancer cells induce co-resistant phenotypes in neighboring cancer cells when exposed to cancer therapy. Using a CRISPR/Cas9 toolkit we engineered phenotypically diverse non-small cell lung cancer (NSCLC) cells by conferring mutations in Dicer1, a type III cytoplasmic endoribonuclease involved in small non-coding RNA genesis. We monitored three-dimensional growth dynamics of fluorescently-labeled mutant and/or wild-type cells individually or in co-culture using a substrate-free NanoCulture system under unstimulated or drug pressure conditions. By integrating mathematical modeling with flow cytometry, we characterized the growth patterns of mono- and co-cultures using a mathematical model of intra- and interspecies competition. Leveraging the flow cytometry data, we estimated the model's parameters to reveal that the combination of WT and mutants in co-cultures allowed for beneficial growth in previously drug sensitive cells despite drug pressure via induction of cell state transitions described by a cooperative game theoretic change in the fitness values. Finally, we used an ex vivo human tumor model that predicts clinical response through drug sensitivity analyses and determined that cellular and morphologic heterogeneity correlates to prognostic failure of multiple clinically-approved and off-label drugs in individual NSCLC patient samples. Together, these findings present a new paradox in drug resistance implicating non-genetic cooperation among tumor cells to thwart drug pressure, suggesting that profiling for druggable targets (i.e. mutations) alone may be insufficient to assign effective therapy.


Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/physiopathology , Lung Neoplasms/drug therapy , Lung Neoplasms/physiopathology , Adaptation, Physiological/genetics , CRISPR-Cas Systems , Carcinoma, Non-Small-Cell Lung/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Cell Proliferation/physiology , Coculture Techniques , Computational Biology , Computer Simulation , DEAD-box RNA Helicases/genetics , Drug Resistance, Multiple/genetics , Drug Resistance, Neoplasm/genetics , Humans , Lung Neoplasms/genetics , Models, Biological , Mutation , Ribonuclease III/genetics
9.
PLoS One ; 13(2): e0191109, 2018.
Article En | MEDLINE | ID: mdl-29415026

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression.


Exosomes/metabolism , HSP90 Heat-Shock Proteins/metabolism , Nanotechnology , Neoplastic Stem Cells/pathology , Organoids/pathology , Animals , Cell Hypoxia , Cell Line, Tumor , Gene Expression Profiling , Humans , Lymphatic Metastasis , Mice , Neoplastic Stem Cells/metabolism , Organoids/metabolism
10.
PLoS One ; 11(9): e0162394, 2016.
Article En | MEDLINE | ID: mdl-27622654

Epithelial-mesenchymal transition (EMT) is a crucial pathological event in cancer, particularly in tumor cell budding and metastasis. Therefore, control of EMT can represent a novel therapeutic strategy in cancer. Here, we introduce an innovative three-dimensional (3D) high-throughput screening (HTS) system that leads to an identification of EMT inhibitors. For the establishment of the novel 3D-HTS system, we chose NanoCulture Plates (NCP) that provided a gel-free micro-patterned scaffold for cells and were independent of other spheroid formation systems using soft-agar. In the NCP-based 3D cell culture system, A549 lung cancer cells migrated, gathered, and then formed multiple spheroids within 7 days. Live cell imaging experiments showed that an established EMT-inducer TGF-ß promoted peripheral cells around the core of spheroids to acquire mesenchymal spindle shapes, loss of intercellular adhesion, and migration from the spheroids. Along with such morphological change, EMT-related gene expression signatures were altered, particularly alteration of mRNA levels of ECAD/CDH1, NCAD/CDH2, VIM and ZEB1/TCF8. These EMT-related phenotypic changes were blocked by SB431542, a TGF-ßreceptor I (TGFßR1) inhibitor. Inside of the spheroids were highly hypoxic; in contrast, spheroid-derived peripheral migrating cells were normoxic, revealed by visualization and quantification using Hypoxia Probe. Thus, TGF-ß-triggered EMT caused spheroid hypoplasia and loss of hypoxia. Spheroid EMT inhibitory (SEMTIN) activity of SB431542 was calculated from fluorescence intensities of the Hypoxia Probe, and then was utilized in a drug screening of EMT-inhibitory small molecule compounds. In a pilot screening, 9 of 1,330 compounds were above the thresholds of the SEMTIN activity and cell viability. Finally, two compounds SB-525334 and SU9516 showed SEMTIN activities in a dose dependent manner. SB-525334 was a known TGFßR1 inhibitor. SU9516 was a cyclin-dependent kinase 2 (CDK2) inhibitor, which we showed also had an EMT-inhibitory activity. The half maximal inhibitory concentration (IC50) of SB-525334 and SU9516 were 0.31 µM and 1.21 µM, respectively, while IC50 of SB431542 was 2.38 µM. Taken together, it was shown that this 3D NCP-based HTS system was useful for screening of EMT-regulatory drugs.


Cyclin-Dependent Kinase 2/antagonists & inhibitors , Drug Screening Assays, Antitumor/methods , Epithelial-Mesenchymal Transition/drug effects , Imidazoles/pharmacology , Indoles/pharmacology , Benzamides/pharmacology , Cell Hypoxia/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Dioxoles/pharmacology , Drug Screening Assays, Antitumor/instrumentation , Humans , Pilot Projects , Spheroids, Cellular , Transforming Growth Factor beta2/pharmacology
11.
PLoS One ; 8(11): e80392, 2013.
Article En | MEDLINE | ID: mdl-24303010

The completion of cytokinesis is crucial for mitotic cell division. Cleavage furrow ingression is followed by the breaking and resealing of the intercellular bridge, but the detailed mechanism underlying this phenomenon remains unknown. Katanin is a microtubule-severing protein comprised of an AAA ATPase subunit and an accessory subunit designated as p60 and p80, respectively. Localization of katanin p60 was observed at the midzone to midbody from anaphase to cytokinesis in rat cells, and showed a ring-shaped distribution in the gap between the inside of the contractile ring and the central spindle bundle in telophase. Katanin p60 did not bind with p80 at the midzone or midbody, and localization was shown to be dependent on microtubules. At the central spindle and the midbody, no microtubule growth plus termini were seen with katanin p60, and microtubule density was inversely correlated with katanin p60 density in the region of katanin p60 localization that seemed to lead to microtubule destabilization at the midbody. Inhibition of katanin p60 resulted in incomplete cytokinesis by regression and thus caused the appearance of binucleate cells. These results suggest that katanin p60 contributes to microtubule instability at the midzone and midbody and facilitates cytokinesis in rat cells.


Adenosine Triphosphatases/metabolism , Cytokinesis/physiology , Microtubules/metabolism , Animals , Cell Line , Katanin , Mitosis , Protein Transport , Rats , Spindle Apparatus/metabolism
12.
Proteomics ; 13(15): 2351-60, 2013 Aug.
Article En | MEDLINE | ID: mdl-23712969

Chemoresistance is one of the most critical prognostic factors in osteosarcoma, and elucidation of the molecular backgrounds of chemoresistance may lead to better clinical outcomes. Spheroid cells resemble in vivo cells and are considered an in vitro model for the drug discovery. We found that spheroid cells displayed more chemoresistance than conventional monolayer cells across 11 osteosarcoma cell lines. To investigate the molecular mechanisms underlying the resistance to chemotherapy, we examined the proteomic differences between the monolayer and spheroid cells by 2D-DIGE. Of the 4762 protein species observed, we further investigated 435 species with annotated mass spectra in the public proteome database, Genome Medicine Database of Japan Proteomics. Among the 435 protein species, we found that 17 species exhibited expression level differences when the cells formed spheroids in more than five cell lines and four species out of these 17 were associated with spheroid-formation associated resistance to doxorubicin. We confirmed the upregulation of cathepsin D in spheroid cells by western blotting. Cathepsin D has been implicated in chemoresistance of various malignancies but has not previously been implemented in osteosarcoma. Our study suggested that the spheroid system may be a useful tool to reveal the molecular backgrounds of chemoresistance in osteosarcoma.


Antineoplastic Agents/pharmacology , Bone Neoplasms/drug therapy , Bone Neoplasms/metabolism , Osteosarcoma/drug therapy , Osteosarcoma/metabolism , Proteome/metabolism , Bone Neoplasms/pathology , Cell Line, Tumor , Drug Resistance, Neoplasm , Electrophoresis, Gel, Two-Dimensional , Humans , Osteosarcoma/pathology , Proteome/analysis , Proteomics , Spheroids, Cellular
13.
Chem Commun (Camb) ; (7): 840-1, 2004 Apr 07.
Article En | MEDLINE | ID: mdl-15045090

The 12 wt% Pt-deposited carbon nanotube electrode gives 10% higher voltages than 29 wt% Pt-deposited carbon black and reduces the Pt usage by 60% in polymer electrolyte fuel cells with hydrogen and oxygen.

14.
J Biochem ; 135(1): 71-8, 2004 Jan.
Article En | MEDLINE | ID: mdl-14999011

In order to discover novel invertebrate cytokines from the budding tunicate, Polyandrocarpa misakiensis, we treated the water-insoluble fraction of tunicate homogenates with trypsin. The extracts showed remarkable activities to promote the growth and motility of tunicate cells. The activities were heat-stable and proteinase K-resistant. After anion exchange chromatography, the activities were eluted with detergents such as 0.1% deoxycholic acid. The Fourier transform infrared spectrum indicated large amounts of fatty acids and phospholipids instead of polypeptides in the extracts. Consistently, the activities were extractable with organic solvents such as chloroform. Long chains of n-3 polyunsaturated free fatty acids (FFA), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) were the major components in the lipid-soluble fraction. A cDNA for FFA-releasing enzyme phospholipase A(2) (PLA(2)) was cloned. The expression of this gene could be seen in epidermal cells during budding. The recombinant protein, as in the case of the authentic PLA2, preferred PC and PE as substrates, followed by PS and PI. The resultant FFAs only promoted cell growth, while the remaining lysophospholipids stimulated cell motility. The former contained unsaturated fatty acids (C18:1, C20:5, and C22:6) while the latter did not, suggesting that unsaturated fatty acids are responsible for mitogenic activity in tunicate cells. These results show for the first time that phospholipids and their derivatives are bio-mediators promoting cell growth and cell motility in invertebrates.


Mitogens/pharmacology , Phospholipids/pharmacology , Urochordata/cytology , Urochordata/growth & development , Amino Acid Sequence , Animals , Cell Movement/drug effects , Cell Movement/genetics , Cell-Free System/physiology , Cells, Cultured , Mitogens/genetics , Mitogens/isolation & purification , Molecular Sequence Data , Phospholipids/genetics , Phospholipids/isolation & purification , Urochordata/genetics
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