Angiotensin-converting enzyme 2 (ACE2) is critically involved in cardiovascular physiology and pathology, and is currently clinically evaluated to treat acute lung failure. Here we show that the ...B38-CAP, a carboxypeptidase derived from Paenibacillus sp. B38, is an ACE2-like enzyme to decrease angiotensin II levels in mice. In protein 3D structure analysis, B38-CAP homolog shares structural similarity to mammalian ACE2 with low sequence identity. In vitro, recombinant B38-CAP protein catalyzed the conversion of angiotensin II to angiotensin 1-7, as well as other known ACE2 target peptides. Treatment with B38-CAP suppressed angiotensin II-induced hypertension, cardiac hypertrophy, and fibrosis in mice. Moreover, B38-CAP inhibited pressure overload-induced pathological hypertrophy, myocardial fibrosis, and cardiac dysfunction in mice. Our data identify the bacterial B38-CAP as an ACE2-like carboxypeptidase, indicating that evolution has shaped a bacterial carboxypeptidase to a human ACE2-like enzyme. Bacterial engineering could be utilized to design improved protein drugs for hypertension and heart failure.
Here we report the discovery of oncogenic mutations in the Hedgehog and mitogen-activated protein kinase (MAPK) pathways in over 80% of ameloblastomas, locally destructive odontogenic tumors of the ...jaw, by genomic analysis of archival material. Mutations in SMO (encoding Smoothened, SMO) are common in ameloblastomas of the maxilla, whereas BRAF mutations are predominant in tumors of the mandible. We show that a frequently occurring SMO alteration encoding p.Leu412Phe is an activating mutation and that its effect on Hedgehog-pathway activity can be inhibited by arsenic trioxide (ATO), an anti-leukemia drug approved by the US Food and Drug Administration (FDA) that is currently in clinical trials for its Hedgehog-inhibitory activity. In a similar manner, ameloblastoma cells harboring an activating BRAF mutation encoding p.Val600Glu are sensitive to the BRAF inhibitor vemurafenib. Our findings establish a new paradigm for the diagnostic classification and treatment of ameloblastomas.
Idiopathic pure red cell aplasia (PRCA) and secondary PRCA associated with thymoma and large granular lymphocyte leukemia are generally considered to be immune-mediated. The PRCA2004/2006 study ...showed that poor responses to immunosuppression and anemia relapse were associated with death. PRCA may represent the prodrome to MDS. Thus, clonal hematopoiesis may be responsible for treatment failure. We investigated gene mutations in myeloid neoplasm-associated genes in acquired PRCA. We identified 21 mutations affecting amino acid sequences in 11 of the 38 adult PRCA patients (28.9%) using stringent filtering of the error-prone sequences and SNPs. Four PRCA patients showed 7 driver mutations in TET2, DNMT3A and KDM6A, and 2 PRCA patients carried multiple mutations in TET2. Five PRCA patients had mutations with high VAFs exceeding 0.3. These results suggest that clonal hematopoiesis by stem/progenitor cells might be related to the pathophysiology of chronic PRCA in certain adult patients.
Purpose
To establish whether Sphingosine-1-phosphate (S1P) and sphingosine kinase 1 (SphK1) contribute to lymph node metastasis in esophageal squamous cell carcinoma.
Methods
Immunohistochemical ...analysis of SphK1 expression was performed using a tissue microarray containing 177 thoracic squamous cell esophageal cancer specimens resected at surgery, to investigate the association between intratumoral SphK1 expression and lymph node metastasis. Serum S1P levels and intratumoral SphK1 mRNA and protein expression were also evaluated in mice with vs. mice without lymph node metastasis in a murine lymph node metastasis model.
Results
Among 177 esophageal cancer patients, 127 (72%) were defined as being SphK1-positive. In univariate and multivariate analyses, SphK1 expression status was a significant factor contributing to lymph node metastasis and poorer 5-year overall survival. In the murine lymph node metastasis model, there was no difference in tumor volume or weight between the lymph node metastasis-negative and lymph node metastasis-positive groups. However, levels of SphK1 mRNA and protein and serum S1P levels were all much higher in the metastasis-positive group.
Conclusions
S1P/SphK1 may be novel targets for inhibiting lymph node metastasis in esophageal squamous cell carcinoma, and may provide the basis for a therapeutic strategy to suppress lymph node metastasis.
Pharmacological interventions to enhance fibrinolysis are effective for treating thrombotic disorders. Utilizing the in vitro U937 cell line-based fibrin degradation assay, we had previously found a ...cyclic pentapeptide malformin A
(MA
) as a novel activating compound for cellular fibrinolytic activity. The mechanism by which MA
enhances cellular fibrinolytic activity remains unknown. In the present study, we show that RSK1 is a crucial mediator of MA
-induced cellular fibrinolysis. Treatment with rhodamine-conjugated MA
showed that MA
localizes mainly in the cytoplasm of U937 cells. Screening with an antibody macroarray revealed that MA
induces the phosphorylation of RSK1 at Ser380 in U937 cells. SL0101, an inhibitor of RSK, inhibited MA
-induced fibrinolytic activity, and CRISPR/Cas9-mediated knockout of RSK1 but not RSK2 suppressed MA
-enhanced fibrinolysis in U937 cells. Synthetic active MA
derivatives also induced the phosphorylation of RSK1. Furthermore, MA
treatment stimulated phosphorylation of ERK1/2 and MEK1/2. PD98059, an inhibitor of MEK1/2, inhibited MA
-induced phosphorylation of RSK1 and ERK1/2, indicating that MA
induces the activation of the MEK-ERK-RSK pathway. Moreover, MA
upregulated the expression of urokinase-type plasminogen activator (uPA) and increased uPA secretion. These inductions were abrogated in RSK1 knockout cells. These results indicate that RSK1 is a key regulator of MA
-induced extracellular fibrinolytic activity.
Cadmium is a toxic pollutant with occupational and environmental significance, due to its diverse toxic effects. Supramolecules that conjugate and decontaminate toxic metals have potential for use in ...treatment of cadmium intoxication. In addition, metal‐coordinating ability has been postulated to contribute to the cytotoxic effects of anti‐tumor agents such as cisplatin or bleomycin. Thiacalixarenes, cyclic oligomers of p‐alkylphenol bridged by sulfur atoms, are supramolecules known to have potent coordinating ability to metal ions. In this study, we show that cadmium‐coordinated thiacalix4arene tetrasulfate (TC4ATS‐Cd) exhibits an anti‐proliferative effect against T‐cell leukemia cells. Cadmium exhibited cytotoxicity with IC50 values ranging from 36 to 129 μM against epithelia‐derived cancer cell lines, while TC4ATS‐Cd elicited no significant cytotoxicity (IC50 > 947 μM). However, a number of T‐cell leukemia cell lines exhibited marked sensitivity to TC4ATS‐Cd. In Jurkat cells, toxicity of TC4ATS‐Cd occurred with an IC50 of 6.9 μM, which is comparable to that of 6.5 μM observed for cadmium alone. TC4ATS‐Cd induced apoptotic cell death through activation of caspase‐3 in Jurkat cells. In a xenograft model, TC4ATS‐Cd (13 mg/kg) treatment significantly suppressed the tumor growth of Jurkat cells in mice. In addition, TC4ATS‐Cd‐treated mice exhibited significantly less cadmium accumulation in liver and kidney compared to equimolar cadmium‐treated mice. These results suggest that cadmium‐coordinated supramolecules may have therapeutic potential for treatment of T‐cell leukemia.
We found that thiacalixarene‐cadmium complex has an anti‐proliferative effect against T‐cell leukemia cells, with no cytotoxicity in epithelia‐derived cancer cells in vitro and minimum accumulations of cadmium in mice. In xenograft tumor model, cadmium‐complex treatment significantly suppressed tumor growth of Jurkat cells in mice. These results suggest that thiacalixarene‐cadmium complex may have therapeutic potential for treatment of T‐cell leukemia.
Glechoma hederacea L. (Labiatae) has been used in folk medicine to treat various ailments for centuries. We investigated the effects of G. hederacea extract on melanogenesis in B16 melanoma cells. It ...significantly reduced both the cellular melanin content and tyrosinase activity in a concentration-dependent manner. An MTT assay did not reveal any obvious cytotoxicity. Furthermore, we found that G. hederacea extract decreased tyrosinase and microphthalmia-associated transcription factor protein expression, but did not inhibit tyrosinase-related protein-1 and tyrosinase-related protein-2 expression. RT-PCR analysis indicated that the antimelanogenic effect of G. hederacea extract might be due to inhibition of tyrosinase gene transcription. Moreover, this effect is regulated via suppression of microphthalmia-associated transcription factor protein expression. Our data indicate that G. hederacea extract inhibits melanin synthesis in B16 melanoma cells but is not cytotoxic. Hence it might prove a useful therapeutic agent for treating hyperpigmentation and an effective component of whitening cosmetics.
Identification of reliable markers of chemo‐ and radiosensitivity and the key molecules that enhance the susceptibility of squamous esophageal cancer cells to anticancer treatments would be highly ...desirable. To test whether regenerating gene (REG) I expression enhances chemo‐ and radiosensitivity in esophageal squamous cell carcinoma cells, we used MTT (3‐4,5‐dimethylthiazol‐2‐yl‐2,5‐diphenyltetrazolium bromide) assays to compare the chemo‐ and radiosensitivities of untransfected TE‐5 and TE‐9 cells with those of cells stably transfected with REG Iα and Iβ. We then used flow cytometry to determine whether REG I expression alters cell cycle progression. No REG I mRNA or protein were detected in untransfected TE‐5 and TE‐9 cells. Transfection with REG Iα and Iβ led to strong expression of both REG I mRNA and protein in TE‐5 and TE‐9 cells, which in turn led to significant increases in both chemo‐ and radiosensitivity. Cell cycle progression was unaffected by REG I expression. REG I thus appears to enhance the chemo‐ and radiosensitivity of squamous esophageal cancer cells, which suggests that it may be a useful target for improved and more individualized treatments for patients with esophageal squamous cell carcinoma. (Cancer Sci 2008; 99: 2491–2495)
Tooth root formation begins after the completion of crown morphogenesis. At the end edge of the tooth crown, inner and outer enamel epithelia form Hertwig's epithelial root sheath (HERS). HERS ...extends along with dental follicular tissue for root formation. Ameloblastin (AMBN) is an enamel matrix protein secreted by ameloblasts and HERS derived cells. A number of enamel proteins are eliminated in root formation, except for AMBN. AMBN may be related to tooth root formation; however, its role in this process remains unclear. In this study, we found AMBN in the basal portion of HERS of lower first molar in mice, but not at the tip. We designed and synthesized small interfering RNA (siRNA) targeting AMBN based on the mouse sequence. When AMBN siRNA was injected into a prospective mandibular first molar of postnatal day 10 mice, the root became shorter 10 days later. Furthermore, HERS in these mice revealed a multilayered appearance and 5-bromo-2'-deoxyuridine (BrdU) positive cells increased in the outer layers. In vitro experiments, when cells were compared with and without transiently expressing AMBN mRNA, expression of growth suppressor genes such as p21(Cip1) and p27(Kip1) was enhanced without AMBN and BrdU incorporation increased. Thus, AMBN may regulate differentiation state of HERS derived cells. Moreover, our results suggest that the expression of AMBN in HERS functions as a trigger for normal root formation.
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