Chemical modification of bradykinin-polymer conjugates for optimum delivery of nanomedicines to tumors.

We recently prepared pH-responsive HPMA copolymer conjugates of bradykinin (P-BK), which release BK in response to the acidic tumor microenvironment, and found that administration of P-BK increased the tumor accumulation and therapeutic efficacy of nanomedicine. Because the release of BK from P-BK determines its onset of action, P-BKs with different release rates were prepared, and their properties were evaluated. The release kinetics were significantly altered by substitution proximal to hydrazone bond, release constant of methyl-substituted P-BK (P-MeBK) was approximately 4- and 80-fold higher than that of cyclopropyl-substituted P-BK (P-CPBK) and phenyl-substituted P-BK (P-PhBK). None of the P-BKs were active, but the release of BK restored their BK-like activity. Pre-administration of the P-BKs increased the tumor accumulation of nanomedicine in C26 tumor-bearing mice by 2- and 1.4-fold for P-MeBK and P-PhBK at 3 and 6 h. Altogether, this study provides insights into the design of pH-responsive nanodrugs with the desired release properties to target acidic lesions such as cancer and inflammation.

Hypoxia-inducible factor-1α and poly [ADP ribose] polymerase 1 cooperatively regulate Notch3 expression under hypoxia via a noncanonical mechanism.

Upregulation of Notch3 expression has been reported in many cancers and is considered a marker for poor prognosis. Hypoxia is a driving factor of the Notch3 signaling pathway; however, the induction mechanism and role of hypoxia-inducible factor-1α (HIF-1α) in the Notch3 response are still unclear. In this study, we found that HIF-1α and poly [ADP-ribose] polymerase 1 (PARP-1) regulate Notch3 induction under hypoxia via a noncanonical mechanism. In the analyzed cancer cell lines, Notch3 expression was increased during hypoxia at both the mRNA and protein levels. HIF-1α knockdown and Notch3 promoter reporter analyses indicated that the induction of Notch3 by hypoxia requires HIF-1α and also another molecule that binds the Notch3 promoter's guanine-rich region, which lacks the canonical hypoxia response element. Therefore, using mass spectrometry analysis to identify the binding proteins of the Notch3 promoter, we found that PARP-1 specifically binds to the Notch3 promoter. Interestingly, analyses of the Notch3 promoter reporter and knockdown of PARP-1 revealed that PARP-1 plays an important role in Notch3 regulation. Furthermore, we demonstrate that PARP inhibitors, including an inhibitor specific for PARP-1, attenuated the induction of Notch3 by hypoxia. These results uncover a novel mechanism in which HIF-1α associates with PARP-1 on the Notch3 promoter in a hypoxia response element-independent manner, thereby inducing Notch3 expression during hypoxia. Further studies on this mechanism could facilitate a better understanding of the broader functions of HIF-1α, the roles of Notch3 in cancer formation, and the insights into novel therapeutic strategies.

Anti-cancer effect of afatinib, dual inhibitor of HER2 and EGFR, on novel mutation HER2 E401G in models of patient-derived cancer.

BACKGROUND: Precision medicine with gene panel testing based on next-generation sequencing for patients with cancer is being used increasingly in clinical practice. HER2, which encodes the human epidermal growth factor receptor 2 (HER2), is a potentially important driver gene. However, therapeutic strategies aimed at mutations in the HER2 extracellular domain have not been clarified. We therefore investigated the effect of EGFR co-targeted therapy with HER2 on patient-derived cancer models with the HER2 extracellular domain mutation E401G, based on our previous findings that this mutation has an epidermal growth factor receptor (EGFR)-mediated activation mechanism. METHODS: We generated a xenograft (PDX) and a cancer tissue-originated spheroid (CTOS) from a patient's cancer containing an amplified HER2 E401G mutation. With these platforms, we compared the efficacy of afatinib, a tyrosine kinase inhibitor having anti-HER2 and anti-EGFR activity, with two other therapeutic options: lapatinib, which has similar properties but weaker EGFR inhibition, and trastuzumab plus pertuzumab, for which evidence exists of treatment efficacy against cancers with wild-type HER2 amplification. Similar experiments were also performed with H2170, a cell line with wild-type HER2 amplification, to contrast the characteristics of these drug's efficacies against HER2 E401G. RESULTS: We confirmed that PDX and CTOS retained morphological and immunohistochemical characteristics and HER2 gene profiles of the original tumor. In both PDX and CTOS, afatinib reduced tumor size more than lapatinib or trastuzumab plus pertuzumab. In addition, afatinib treatment resulted in a statistically significant reduction in HER2 copy number at the end of treatment. On the other hand, in H2170 xenografts with wild-type HER2 amplification, trastuzumab plus pertuzumab was most effective. CONCLUSIONS: Afatinib, a dual inhibitor of HER2 and EGFR, showed a promising effect on cancers with amplified HER2 E401G, which have an EGFR-mediated activation mechanism. Analysis of the activation mechanisms of mutations and development of therapeutic strategies based on those mechanisms are critical in precision medicine for cancer patients.

Targeting aberrant DNA hypermethylation as a driver of ATL leukemogenesis by using the new oral demethylating agent OR-2100.

Adult T-cell leukemia-lymphoma (ATL) is an aggressive hematological malignancy of CD4+ T cells transformed by human T-cell lymphotropic virus-1 (HTLV-1). Most HTLV-1-infected individuals are asymptomatic, and only 3% to 5% of carriers develop ATL. Here, we describe the contribution of aberrant DNA methylation to ATL leukemogenesis. HTLV-1-infected T-cells and their uninfected counterparts were separately isolated based on CADM1 and CD7 expression status, and differentially methylated positions (DMPs) specific to HTLV-infected T cells were identified through genome-wide DNA methylation profiling. Accumulation of DNA methylation at hypermethylated DMPs correlated strongly with ATL development and progression. In addition, we identified 22 genes downregulated because of promoter hypermethylation in HTLV-1-infected T cells, including THEMIS, LAIR1, and RNF130, which negatively regulate T-cell receptor (TCR) signaling. Phosphorylation of ZAP-70, a transducer of TCR signaling, was dysregulated in HTLV-1-infected cell lines but was normalized by reexpression of THEMIS. Therefore, we hypothesized that DNA hypermethylation contributes to growth advantages in HTLV-1-infected cells during ATL leukemogenesis. To test this idea, we investigated the anti-ATL activities of OR-1200 and OR-2100 (OR21), novel decitabine (DAC) prodrugs with enhanced oral bioavailability. Both DAC and OR21 inhibited cell growth, accompanied by global DNA hypomethylation, in xenograft tumors established by implantation of HTLV-1-infected cells. OR21 was less hematotoxic than DAC, whereas tumor growth inhibition was almost identical between the 2 compounds, making it suitable for long-term treatment of ATL patient-derived xenograft mice. Our results demonstrate that regional DNA hypermethylation is functionally important for ATL leukemogenesis and an effective therapeutic target.

Assessment of postoperative common bile duct stones after endoscopic extraction and subsequent cholecystectomy.

BACKGROUND: Common bile duct stones (CBDSs) occasionally cause serious diseases, and endoscopic extraction is the standard procedure for CBDS. To prevent biliary complications, cholecystectomy is recommended for patients who present with gallbladder (GB) stones after endoscopic CBDS extraction. However, CBDS can occasionally recur. To date, the occurrence of CBDS after endoscopic CBDS extraction and subsequent cholecystectomy is not fully understood. Hence, the current study aimed to evaluate the incidence of postoperative CBDSs. METHODS: This retrospective observational study included consecutive patients who underwent postoperative endoscopic retrograde cholangiography after endoscopic CBDS extraction and subsequent cholecystectomy between April 2012 and June 2021 at our institution. After endoscopic CBDS extraction, a biliary plastic stent was inserted to prevent obstructive cholangitis. Endoscopic retrograde cholangiography was performed to evaluate postoperative CBDSs after cholecystectomy until hospital discharge. The outcomes were the incidence of postoperative CBDSs and CBDSs/sludge. Moreover, the predictive factors for postoperative CBDSs were evaluated via univariate and multivariate analyses. RESULTS: Of eligible 204 patients, 52 patients (25.5%) presented with postoperative CBDSs. The incidence rate of CBDS/sludge was 36.8% (n = 75). Based on the univariate analysis, the significant predictive factors for postoperative CBDSs were ≥ 6 CBDSs, presence of cystic duct stones, and ≥ 10 GB stones (P < 0.05). Moreover, male sex and < 60-mm minor axis in GB might be predictive factors (P < 0.10). Based on the multivariate analysis, ≥ 6 CBDSs (odds ratio = 6.65, P < 0.01), presence of cystic duct stones (odds ratio = 4.39, P < 0.01), and ≥ 10 GB stones (odds ratio = 2.55, P = 0.01) were independent predictive factors for postoperative CBDSs. CONCLUSIONS: The incidence of postoperative CBDS was relatively high. Hence, patients with predictive factors for postoperative CBDS must undergo imaging tests or additional endoscopic procedure after cholecystectomy.

[A case of rectal submucosal tumor diagnosed with the coexistence of gastrointestinal neuroendocrine tumor G1 and adenocarcinoma following endoscopic submucosal dissection].

In a 67-year-old man, colonoscopy confirmed the presence of a 5-6mm submucosal tumor in the upper rectum (Ra);the tumor showed a tendency to grow with the size appearing to be 9-10mm at re-examination that was performed 1 year thereafter. No findings on computed tomography indicated metastasis. A neuroendocrine tumor (NET) was suspected, and endoscopic submucosal dissection was performed. The patient was pathologically diagnosed with coexistence of NETG1 and a well-differentiated adenocarcinoma. Few reports have described the coexistence of relatively low-grade NETG1 and an adenocarcinoma in the Ra, and such an occurrence is considered rare. The patient has shown no recurrence at 3 years and 2 months postoperatively.

GLIS1, a novel hypoxia-inducible transcription factor, promotes breast cancer cell motility via activation of WNT5A.

We previously demonstrated that expression of a Krüppel-like zinc finger transcription factor, GLIS1, dramatically increases under hypoxic conditions via a transcriptional mechanism induced by HIF-2α cooperating with AP-1 members. In this study, we focused on the functional roles of GLIS1 in breast cancer. To uncover its biological function, the effects of altered levels of GLIS1 in breast cancer cell lines on cellular growth, wound-healing and invasion capacities were assessed. Knockdown of GLIS1 using siRNA in BT-474 cells resulted in significant growth stimulation under normoxia, while attenuation was found in the cell invasion assay under hypoxic conditions. In MDA-MB-231 cells expressing exogenous 3xFLAG-tagged GLIS1, GLIS1 attenuated cell proliferation and enhanced cell mobility and invasion capacities under normoxia. In addition, breast cancer cells expressing GLIS1 acquired resistance to irradiation. Whole transcriptome analysis clearly demonstrated that downstream signals of GLIS1 are related to various cellular functions. Among the genes with increased expression, we focused on WNT5A. Knockdown of WNT5A indicated that enhancement of acquired cell motility in the MDA-MB-231 cells expressing GLIS1 was mediated, at least in part, by WNT5A. In an analysis of publicly available data, patients with estrogen receptor-negative breast cancer showing high levels of GLIS1 expression showed much worse prognosis than those with low levels. In summary, hypoxia-induced GLIS1 plays significant roles in breast cancer cells via regulation of gene expression related to cell migration and invasion capacities, resulting in poorer prognosis in patients with advanced breast cancer.

Superior Penetration and Cytotoxicity of HPMA Copolymer Conjugates of Pirarubicin in Tumor Cell Spheroid.

N-(2-Hydroxypropyl)methacrylamide copolymer conjugates of pirarubicin (THP), P-THP, accumulates selectively in solid tumor tissue by the enhanced permeability and retention (EPR) effect. Despite of high accumulation in solid tumors, some macromolecular antitumor agents show poor therapeutic outcome because of poor tissue diffusion into the tumor as well as obstructed tumor blood flow. Here, we confirmed that cellular uptake of P-THP was 25 times less than that of free THP at 1-4 h incubation time in vitro. The passage of P-THP through the confluent tight-monolayer cells junction was 12 times higher than free THP, and P-THP penetrated deeper into the tumor cell spheroid (1.3-1.7-fold) than free THP in 4 h. In addition, P-THP showed cytotoxicity comparable to that of free THP to tumor-cells in spheroid form, despite of 7 times lower cytotoxicity of P-THP to the monolayer cells to that of free THP in vitro. These results indicate that P-THP administration can exhibit deeper diffusion into the tumor cell spheroid than free THP. As a consequence, P-THP exhibits more efficient antitumor activity than free THP in vivo, which is also supported by better pharmacokinetics and tumor accumulation of P-THP than free THP.

The role of vimentin in the tumor marker Nup88-dependent multinucleated phenotype.

BACKGROUND: Nucleoporin Nup88, a component of nuclear pore complexes, is known to be overexpressed in several types of tumor tissue. The overexpression of Nup88 has been reported to promote the early step of tumorigenesis by inducing multinuclei in both HeLa cells and a mouse model. However, the molecular basis of how Nup88 leads to a multinucleated phenotype remains unclear because of a lack of information concerning its binding partners. In this study, we characterize a novel interaction between Nup88 and vimentin. We also examine the involvement of vimentin in the Nup88-dependent multinucleated phenotype. METHODS: Cells overexpressing tagged versions of Nup88, vimentin and their truncations were used in this study. Coprecipitation and GST-pulldown assays were carried out to analyze protein-protein interactions. Vimentin knockdown by siRNA was performed to examine the functional role of the Nup88-vimentin interaction in cells. The phosphorylation status of vimentin was analyzed by immunoblotting using an antibody specific for its phosphorylation site. RESULTS: Vimentin was identified as a Nup88 interacting partner, although it did not bind to other nucleoporins, such as Nup50, Nup214, and Nup358, in HeLa cell lysates. The N-terminal 541 amino acid residues of Nup88 was found to be responsible for its interaction with vimentin. Recombinant GST-tagged Nup88 bound to recombinant vimentin in a GST-pulldown assay. Although overexpression of Nup88 in HeLa cells was observed mainly at the nuclear rim and in the cytoplasm, colocalization with vimentin was only partially detected at or around the nuclear rim. Disruption of the Nup88-vimentin interaction by vimentin specific siRNA transfection suppressed the Nup88-dependent multinucleated phenotype. An excess amount of Nup88 in cell lysates inhibited the dephosphorylation of a serine residue (Ser83) within the vimentin N-terminal region even in the absence and presence of an exogenous phosphatase. The N-terminal 96 amino acid residues of vimentin interacted with both full-length and the N-terminal 541 residues of Nup88. CONCLUSIONS: Nup88 can affect the phosphorylation status of vimentin, which may contribute to the Nup88-dependent multinucleated phenotype through changing the organization of vimentin.

Current status of water environment and their microbial biosensor techniques - Part I: Current data of water environment and recent studies on water quality investigations in Japan, and new possibility of microbial biosensor techniques.

In my 2010 review, I addressed conventional water analysis and biosensing of organic pollutants in Japan between 1960s and 2000s. It is now timely to reexamine current analytical and biomonitoring approaches in view of the new challenges in assessing pollution, particularly in closed water bodies, as pollutants tend to accumulate in these endorheic basins. In the present review series, I presented current water environment and its microbial biosensors. In this part, I presented current data of the water quality of these water bodies in Japan and established the need to further develop microbial biosensor technologies to address and monitor water quality here. Graphical Abstract Current water pollution indirectly occurring by anthropogenic eutrophication (Part I).

Current status of water environment and their microbial biosensor techniques - Part II: Recent trends in microbial biosensor development.

In Part I of the present review series, I presented the current state of the water environment by focusing on Japanese cases and discussed the need to further develop microbial biosensor technologies for the actual water environment. I comprehensively present trends after approximately 2010 in microbial biosensor development for the water environment. In the first section, after briefly summarizing historical studies, recent studies on microbial biosensor principles are introduced. In the second section, recent application studies for the water environment are also introduced. Finally, I conclude the present review series by describing the need to further develop microbial biosensor technologies. Graphical abstract Current water pollution indirectly occurs by anthropogenic eutrophication (Part I). Recent trends in microbial biosensor development for water environment are described in part II of the present review series.

Preparation and in Vitro Analysis of Human Serum Albumin Nanoparticles Loaded with Anthracycline Derivatives.

Nanoparticles prepared using human serum albumin (HSA) have emerged as versatile carriers for improving the pharmacokinetic profile of drugs. The desolvation of HSA using ethanol followed by stabilization through crosslinking with glutaraldehyde is a common technique for preparing HSA nanoparticles, but our knowledge concerning the characteristics (or functions) of HSA nanoparticles and their efficiency when loaded with drugs is limited. To address this issue in more detail, we prepared anthracycline-loaded HSA nanoparticles. Doxorubicin-loaded HSA nanoparticles with a size similar to doxorubicin-unloaded particles could be prepared by desolvating at a higher pH (8-9), and the size (100-150 nm) was optimum for delivery to tumor tissues. Using this procedure, HSA nanoparticles were loaded with other anthracycline derivatives, and all showed cytotoxicity in cancer cells. However, the efficiency of drug loading and dissolution rate were different among them possibly due to the differences in the type of association of the drugs on nanoparticles (doxorubicin and daunorubicin; covalently bound to nanoparticles, pirarubicin; both covalently bound to and adsorbed on nanoparticles, aclarubicin; adsorbed on nanoparticles). Since the formulation of such drug-loaded HSA nanoparticles should be modified for efficient delivery to tumors, the findings reported herein provide the useful information for optimizing the formulation and the production process for the HSA nanoparticles using a desolvation technique.

Losartan attenuates the coronary perivasculitis through its local and systemic anti-inflammatory properties in a murine model of Kawasaki disease.

BACKGROUND: Kawasaki disease is a common systemic vasculitis that leads to coronary artery lesions. Besides its antihypertensive effects, losartan can modulate inflammation in cardiovascular disease. We examined whether losartan can attenuate coronary inflammation in a murine model of Kawasaki disease. METHODS AND RESULTS: Five-wk-old C57/BL6J male mice were intraperitoneally injected with Lactobacillus casei cell wall extract to induce coronary inflammation and divided into four groups: placebo, intravenous immunoglobulin (IVIG), losartan, and IVIG+losartan. After 2 wk, mice were harvested. The coronary perivasculitis was significantly attenuated by losartan but not by IVIG alone, and further dramatic attenuation by IVIG+losartan was observed. The frequency of Lactobacillus casei cell wall extract-induced myocarditis (80%) was markedly lowered by losartan (22%) and IVIG+losartan (0%). Furthermore, interleukin (IL)-6 mRNA was markedly attenuated by IVIG+losartan. Serum levels of IL-6, TNF-α, MCP-1, and IL-10 after Lactobacillus casei cell wall extract injection were slightly decreased by IVIG or losartan. Moreover, IL-1ß, IL-10, and MCP-1 levels were significantly decreased by IVIG+losartan. CONCLUSION: The addition of losartan to IVIG strongly attenuated the severity of coronary perivasculitis and the incidence of myocarditis, along with suppressing systemic/local cytokines as well as the activated macrophage infiltration. Therefore, losartan may be a potentially useful additive drug for the acute phase of Kawasaki disease to minimize coronary artery lesions.

Pronounced Cellular Uptake of Pirarubicin versus That of Other Anthracyclines: Comparison of HPMA Copolymer Conjugates of Pirarubicin and Doxorubicin.

Many conjugates of water-soluble polymers with biologically active molecules were developed during the last two decades. Although, therapeutic effects of these conjugates are affected by the properties of carriers, the properties of the attached drugs appear more important than the same carrier polymer in this case. Pirarubicin (THP), a tetrahydropyranyl derivative of doxorubicin (DOX), demonstrated more rapid cellular internalization and potent cytotoxicity than DOX. Here, we conjugated the THP or DOX to N-(2-hydroxypropyl)methacrylamide copolymer via a hydrazone bond. The polymeric prodrug conjugates, P-THP and P-DOX, respectively, had comparable hydrodynamic sizes and drug loading. Compared with P-DOX, P-THP showed approximately 10 times greater cellular uptake during a 240 min incubation and a cytotoxicity that was more than 10 times higher during a 72-h incubation. A marginal difference was seen in P-THP and P-DOX accumulation in the liver and kidney at 6 h after drug administration, but no significant difference occurred in the tumor drug concentration during 6-24 h after drug administration. Antitumor activity against xenograft human pancreatic tumor (SUIT2) in mice was greater for P-THP than for P-DOX. To sum up, the present study compared the biological behavior of two different drugs, each attached to an N-(2-hydroxypropyl)methacrylamide copolymer carrier, with regard to their uptake by tumor cells, body distribution, accumulation in tumors, cytotoxicity, and antitumor activity in vitro and in vivo. No differences in the tumor cell uptake of the polymer-drug conjugates, P-THP and P-DOX, were observed. In contrast, the intracellular uptake of free THP liberated from the P-THP was 25-30 times higher than that of DOX liberated from P-DOX. This finding indicates that proper selection of the carrier, and especially conjugated active pharmaceutical ingredient (API) are most critical for anticancer activity of the polymer-drug conjugates. THP, in this respect, was found to be a more preferable API for polymer conjugation than DOX. Hence the treatment based on enhanced permeability and retention (EPR) effect that targets more selectively to solid tumors can be best achieved with THP, although both polymer conjugates of DOX and THP exhibited the EPR effects and drug release profiles in acidic pH similarly.

[Missile-Type Tumor-Targeting Polymer Drug, P-THP, Seeks Tumors via Three Different Steps Based on the EPR Effect].

The enhanced permeability and retention (EPR) effect, a tumor-targeting principle of nanomedicine, serves as a standard for tumor-targeted anticancer drug design. There are 3 key issues in ideal EPR-based antitumor drug design: i) stability in blood circulation; ii) tumor-selective accumulation (EPR effect) and efficient release of the active anticancer moiety in tumor tissues; and iii) the active uptake of the active drug into tumor cells. Using these principles, we developed N-(2- hydroxypropyl)methacrylamide (HPMA) copolymer-conjugated pirarubicin (P-THP), which uses hydrazone bond linkage; it was shown to exhibit prolonged circulation time, thereby resulting in good tumor-selective accumulation. More importantly, the hydrazone bond ensured selective and rapid release of the active drug, pirarubicin (THP), in acidic tumor environments. Further, compared to other anthracycline anticancer drugs (eg, doxorubicin), THP demonstrated more rapid intracellular uptake. Consequently, P-THP showed remarkable antitumor effect with minimal side effects. In a clinical pilot study of a stage IV prostate cancer patient with multiple metastases in the lung and bone, P-THP (50-75 mg administered once every 2-3 weeks) was shown to clear the metastatic nodules in the lung almost completely after 3 treatments where 50-70 mg THP equivalent each was administerd per 70 kg body wt, and bone metastasis disappeared after 6 months. There was no recurrence after 2 years. The patient also retained an excellent quality of life during the treatment without any apparent side effects. Thus, we propose the clinical development of P-THP as an EPR-based tumor-targeted anticancer drug.

Synthesis and therapeutic effect of styrene-maleic acid copolymer-conjugated pirarubicin.

Previously, we prepared a pirarubicin (THP)-encapsulated micellar drug using styrene-maleic acid copolymer (SMA) as the drug carrier, in which active THP was non-covalently encapsulated. We have now developed covalently conjugated SMA-THP (SMA-THP conjugate) for further investigation toward clinical development, because covalently linked polymer-drug conjugates are known to be more stable in circulation than drug-encapsulated micelles. The SMA-THP conjugate also formed micelles and showed albumin binding capacity in aqueous solution, which suggested that this conjugate behaved as a macromolecule during blood circulation. Consequently, SMA-THP conjugate showed significantly prolonged circulation time compared to free THP and high tumor-targeting efficiency by the enhanced permeability and retention (EPR) effect. As a result, remarkable antitumor effect was achieved against two types of tumors in mice without apparent adverse effects. Significantly, metastatic lung tumor also showed the EPR effect, and this conjugate reduced metastatic tumor in the lung almost completely at 30 mg/kg once i.v. (less than one-fifth of the maximum tolerable dose). Although SMA-THP conjugate per se has little cytotoxicity in vitro (1/100 of free drug THP), tumor-targeted accumulation by the EPR effect ensures sufficient drug concentrations in tumor to produce an antitumor effect, whereas toxicity to normal tissues is much less. These findings suggest the potential of SMA-THP conjugate as a highly favorable candidate for anticancer nanomedicine with good stability and tumor-targeting properties in vivo.

Microbial Biofilms: Features of Formation and Potential for Use in Bioelectrochemical Devices.

Microbial biofilms present one of the most widespread forms of life on Earth. The formation of microbial communities on various surfaces presents a major challenge in a variety of fields, including medicine, the food industry, shipping, etc. At the same time, this process can also be used for the benefit of humans-in bioremediation, wastewater treatment, and various biotechnological processes. The main direction of using electroactive microbial biofilms is their incorporation into the composition of biosensor and biofuel cells This review examines the fundamental knowledge acquired about the structure and formation of biofilms, the properties they have when used in bioelectrochemical devices, and the characteristics of the formation of these structures on different surfaces. Special attention is given to the potential of applying the latest advances in genetic engineering in order to improve the performance of microbial biofilm-based devices and to regulate the processes that take place within them. Finally, we highlight possible ways of dealing with the drawbacks of using biofilms in the creation of highly efficient biosensors and biofuel cells.

Reprogramming of pyrimidine nucleotide metabolism supports vigorous cell proliferation of normal and malignant T cells.

ABSTRACT: Adult T-cell leukemia/lymphoma (ATL) is triggered by infection with human T-cell lymphotropic virus-1 (HTLV-1). Here, we describe the reprogramming of pyrimidine biosynthesis in both normal T cells and ATL cells through regulation of uridine-cytidine kinase 2 (UCK2), which supports vigorous proliferation. UCK2 catalyzes the monophosphorylation of cytidine/uridine and their analogues during pyrimidine biosynthesis and drug metabolism. We found that UCK2 was overexpressed aberrantly in HTLV-1-infected T cells but not in normal T cells. T-cell activation via T-cell receptor (TCR) signaling induced expression of UCK2 in normal T cells. Somatic alterations and epigenetic modifications in ATL cells activate TCR signaling. Therefore, we believe that expression of UCK2 in HTLV-1-infected cells is induced by dysregulated TCR signaling. Recently, we established azacitidine-resistant (AZA-R) cells showing absent expression of UCK2. AZA-R cells proliferated normally in vitro, whereas UCK2 knockdown inhibited ATL cell growth. Although uridine and cytidine accumulated in AZA-R cells, possibly because of dysfunction of pyrimidine salvage biosynthesis induced by loss of UCK2 expression, the amount of UTP and CTP was almost the same as in parental cells. Furthermore, AZA-R cells were more susceptible to an inhibitor of dihydroorotic acid dehydrogenase, which performs the rate-limiting enzyme of de novo pyrimidine nucleotide biosynthesis, and more resistant to dipyridamole, an inhibitor of pyrimidine salvage biosynthesis, suggesting that AZA-R cells adapt to UCK2 loss by increasing de novo pyrimidine nucleotide biosynthesis. Taken together, the data suggest that fine-tuning pyrimidine biosynthesis supports vigorous cell proliferation of both normal T cells and ATL cells.

Protection from inflammatory bowel disease and colitis-associated carcinogenesis with 4-vinyl-2,6-dimethoxyphenol (canolol) involves suppression of oxidative stress and inflammatory cytokines.

Oxidative stress is associated with various pathological processes including inflammatory bowel disease, which is a major cause of colon cancer. Here, we examined the antioxidative and anti-inflammatory effects of 4-vinyl-2,6-dimethoxyphenol (canolol), a potent antioxidant compound obtained from crude canola oil. Oral administration of 2% dextran sulfate sodium (DSS) resulted in the progression of colitis with shortening of the large bowel length. Administering a diet containing canolol significantly suppressed pathogenesis; diarrhea markedly improved and the length of large bowel returned to almost normal. Pathological examination clearly revealed improvement of colonic ulcers. Production of inflammatory cytokines, i.e. interleukin-12 and tumor necrosis factor-α, was significantly increased during this pathological process; their production was markedly inhibited by canolol. In the azoxymethane/DSS-induced colon cancer model, mice receiving canolol had a reduced occurrence of cancer, to 60%, compared with control mice, 100% of which had colon cancer. The numbers of tumors in each mouse were also significantly reduced in mice receiving the canolol-containing diet (5.6±2.0) compared with azoxymethane/DSS control mice (10.8±4.2). No apparent toxicity of canolol was observed. Moreover, inflammatory cytokines (i.e. cyclooxygenase-2, inducible nitric oxide synthase and tumor necrosis factor-α) and oxidative responding molecules, i.e. heme oxygenase-1, in colon were suppressed during this treatment. In a mouse colon 26 solid tumor model, canolol significantly suppressed cyclooxygenase-2 expression; however, no significant tumor growth inhibition was observed, suggesting that canolol preferably shows chemopreventive effects during the stages of initiation/promotion. Canolol may, thus, be considered a potential cancer preventive agent or supplement.

The Krüppel-like zinc finger transcription factor, GLI-similar 1, is regulated by hypoxia-inducible factors via non-canonical mechanisms.

GLI-similar 1 (GLIS1) is important for the reprogramming of fibroblasts into induced pluripotent stem cells (iPSCs). However, the molecular mechanisms of regulation of GLIS1 expression remain unclear. We have therefore examined GLIS1 expression in various cancer cell lines and demonstrated that GLIS1 expression was dramatically increased under hypoxic conditions. Importantly, GLIS1 expression was significantly attenuated in VHL-overexpressing renal cell carcinoma cells compared to the VHL-deficient parent control. Moreover, promoter analysis demonstrated that GLIS1 transcription was regulated by hypoxia through a hypoxia-inducible factors (HIFs)-dependent mechanism. Co-transfection experiments revealed that HIF-2α had greater potency on the GLIS1 promoter activation than HIF-1α. Subsequent studies using wild-type and mutant HIF-2α demonstrated that DNA binding activity was not necessary but TADs were critical for GLIS1 induction. Finally, co-transfection experiments indicated that HIF-2α cooperated with AP-1 family members in upregulating GLIS1 transcription. These results suggest that the hypoxic signaling pathway may play a pivotal role in regulating the reprogramming factor GLIS1, via non-canonical mechanisms involving partner transcription factor rather than by direct HIF transactivation.