Real Time Observation of Halide Segregation in Mixed Halide Perovskite Solar Cells.

In this work, a novel real-time current-voltage (J-V) absorbance spectroscopy (RTJAS) setup is introduced for directly observing halide segregation in mixed halide perovskite solar cells under broadband light illumination, simulating solar exposure. The setup incorporates a broadband light source calibrated to one sun irradiation and a CMOS camera for simultaneous capture of all diffracted wavelengths. J-V measurements are performed concurrently with absorbance spectra collection, enabling in situ analysis of light-induced degradation due to halide segregation, including bandgap shifts and cell performance data. Comparison of photoluminescence measurements with RTJAS data reveals differing rates of bandgap decrease, underscoring the advantages of real-time measurement techniques. The work highlights the importance of accounting for experimental conditions, such as humidity and voltage injection, which can accelerate halide segregation, ultimately emphasizing the need for careful consideration of experimental conditions to accurately characterize perovskite solar cell behavior under realistic conditions.

Cotargeting Plk1 and androgen receptor enhances the therapeutic sensitivity of paclitaxel-resistant prostate cancer.

BACKGROUNDS: Despite the clinical success of taxanes, they still have limitations, such as chemoresistance. To overcome the limitations of paclitaxel, genetic alterations and targeting effects of altered genes were observed in paclitaxel-resistant cancer. Because paclitaxel-resistant cancer shows high levels of Plk1, a promising target in chemotherapy, the effectiveness of Plk1 inhibitors in paclitaxel-resistant cancer cells has been investigated. METHODS: Paclitaxel-resistant cancer cells were developed by exposure of stepwise escalating levels of paclitaxel. Genetic alterations were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunoblotting. Using a cell viability assay, combined targeting effects for Plk1 and androgen receptor (AR) were determined. Clinical data were analyzed to understand the relationship between Plk1 and AR in prostate cancer patients. RESULTS: Treatment with Plk1 inhibitors markedly reduced the expression of MDR1, MRP1, and Plk1 in the paclitaxel-resistant cancer. Among Plk1 inhibitors, genistein, recently found as a direct Plk1 inhibitor, tended to be more effective in the paclitaxel-resistant prostate cancer than the parental cancer cells, which was related to the suppression of the AR, as well as inhibition of Plk1 activity. A combination of Plk1 inhibitors and AR antagonist bicalutamide exhibited a synergistic effect in LNCaPTXR, as well as LNCaP cells, by inhibiting Plk1 and AR. Analysis of clinical data provides evidence for the relevance between Plk1 and AR in prostate cancer patients, showing that Plk1 and AR are strong predictors of poor survival rates. CONCLUSIONS: We suggest that cotargeting Plk1 and AR would be effective in advanced chemoresistant prostate cancer cells to overcome the limitations associated with paclitaxel.

7-O-Methylwogonin from Scutellaria baicalensis Disturbs Mitotic Progression by Inhibiting Plk1 Activity in Hep3B Cells.

Polo-like kinase 1, a mitotic Ser/Thr kinase, has emerged as a molecular target for the development of anticancer drugs. In this study, we found that polo-like kinase 1 activity was inhibited by 7-O-methylwogonin and related flavones, including baicalein, dihydrobaicalein, and viscidulin II, isolated from Scutellaria baicalensis. Although dihydrobaicalein exhibited the highest polo-like kinase 1 inhibitory activity among the four compounds, it also inhibited other kinases, such as vaccinia-related kinase 2 and polo-like kinase 2. Baicalein and viscidulin II also showed low selectivity to polo-like kinase 1 since they inhibited polo-like kinase 3 and polo-like kinase 2, respectively. However, 7-O-methylwogonin exhibited selective polo-like kinase 1 inhibitory activity, as evidenced from in vitro kinase assays based on fluorescence resonance energy transfer assays and ADP-Glo kinase assays. In addition, examination of mitotic morphology and immunostaining using specific antibodies for the mitotic markers, p-histone H3 and mitotic protein monoclonal 2, in Hep3B cells showed that 7-O-methylwogonin treatment increased mitotic cell populations due to inhibition of mitotic progression as a result of polo-like kinase 1 inhibition. The pattern of 7-O-methylwogonin-induced mitotic arrest was similar to that of BI 2536, a specific polo-like kinase 1 inhibitor. Thus, it was suggested that 7-O-methylwogonin disturbed mitotic progression by inhibiting polo-like kinase 1 activity. These data suggest that 7-O-methylwogonin, a polo-like kinase 1 inhibitor, may be a useful anticancer agent because of its polo-like kinase 1 selectivity and effectiveness.

Comparative Analysis of a FRET-based PLK1 Kinase Assay to Identify PLK1 inhibitors for Chemotherapy.

Advanced techniques for detecting kinase inhibitors are in demand due to limitations of traditional approaches. Here, we used a fluorescence resonance energy transfer (FRET)-based kinase assay, a sensitive fluorescence turn-on biosensing platform, to identify a Polo-like kinase 1 (PLK1) inhibitor. The assay was developed with the Z'-Lyte™ FRET-peptide and PLK1 kinase purified from a baculovirus expression system. Using PLK1 inhibitors, sensitivity and efficiency of this FRET-based PLK1 kinase assay were compared to those of radioisotope-based and immunoblot-based assays. Although the inhibitory activity of BI 2536 against PLK1 kinase in each assay was almost the same, the FRET-based PLK1 kinase assay was much easier, faster, safer, and more convenient than a radioisotope-based assay or an immunoblot-based traditional kinase assay. From our findings, we suggest that a FRET-based PLK1 kinase assay is an advanced tool which overcomes the limitations of previous traditional kinase assays to detect kinase inhibitors for the development of anticancer drugs.

Sensitivity of TP53-Mutated Cancer Cells to the Phytoestrogen Genistein Is Associated With Direct Inhibition of Plk1 Activity.

Polo-like kinase 1 (Plk1), a conserved Ser/Thr mitotic kinase, has been identified as a promising target for anticancer drug development because its overexpression is correlated with malignancy. Here, we found that genistein, an isoflavone, inhibits Plk1 kinase activity directly. Previously the mitotic disturbance phenomenon induced by treatment with genistein was not fully explained by its inhibitory effect on EGFR. In kinase profiling assays, it showed selectivity relative to a panel of kinases, including EGFR. Treatment with genistein induced cell death in a concentration-dependent manner in cancer cells from diverse tissue origins, but not in non-transformed cells such as hTERT-RPE or MCF10A cells. We also observed that genistein tended to be more selective against cancer cells with mutations in the TP53 gene. TP53-depeleted LNCaP and NCI-H460 cells using shRNA targeting human TP53 were more sensitive to cell death by treatment of genistein. Furthermore, genistein induced mitotic arrest by inhibiting Plk1 activity and, consequently, led to mitotic catastrophe and apoptosis. These data suggest that genistein may be a promising anticancer drug candidate due to its inhibitory activity against Plk1 as well as EGFR and effectiveness toward cancer cells, especially those with p53-mutation. J. Cell. Physiol. 232: 2818-2828, 2017. © 2016 Wiley Periodicals, Inc.

Antiinflammatory and analgesic effects of Eurycoma longifolia extracts.

Eurycoma longifolia is one of the most popular herbal medicines in Southeast Asia. The purpose of this study is to evaluate the analgesic and anti-inflammatory effects of the methanolic extract of E. longifolia roots (TA) in vivo and to investigate the underlying mechanisms. TA was tested for analgesic activity by the hot plate test and acetic acid test in mice. The anti-inflammatory effect of TA was observed in carrageenan-induced paw edema in mice. The in vitro molecular study using macrophage cells was performed to elucidate the relevant mechanism. The analgesic activity of 400 mg/kg TA was higher than that of aspirin in the hot plate test. TA also showed analgesic effects in the acetic acid test in a dose-dependent manner. In carrageenan-induced edema in mice, TA showed an anti-inflammatory effect comparable to that of diclofenac. Further in vitro molecular study using macrophage cells revealed that TA suppressed NF-κB translocation to the nucleus, leading to inactivation of the NF-κB signaling pathway and reduction in the expression of cyclooxygenase-2 and inducible nitric oxide synthase. These results exhibited the beneficial effects of TA for alleviating pain and inflammation, which were exerted through inactivation of the NF-κB signaling pathway.

Differential Cellular Effects of Plk1 Inhibitors Targeting the ATP-binding Domain or Polo-box Domain.

The expression of polo-like kinase 1 (Plk1) correlates with malignancy and is thus recognized as a target for cancer therapy. In addition to the development of ATP-competitive Plk1 inhibitors, the polo-box domain (PBD), a unique functional domain of PLKs, is being targeted to develop Plk1-specific inhibitors. However, the action mechanisms of these two classes of Plk1 inhibitors have not been thoroughly evaluated. Here, we evaluate the differences in cellular effects of ATP-binding domain inhibitors (BI 2536, GSK 461364) and PBD inhibitors (poloxin, thymoquinone) to determine their mechanisms of Plk1 inhibition. Our data show that BI 2536 and GSK461364 increased the population of cells in the G2/M phase compared with controls, while treatment with poloxin and thymoquinone increased cell population in the S phase as well as in G2/M, in a p53-independent manner. The population of cells staining positively for p-Histone H3 and MPM2, mitotic index, was increased by treatment with BI 2536 or GSK461364, but not by treatment with poloxin or thymoquinone. Furthermore, treatment with BI 2536 or GSK461364 resulted in activation of the BubR1 spindle checkpoint kinase, suggesting that treatment with ATP-binding domain inhibitors induces metaphase arrest. However, the administration of poloxin and thymoquinone resulted in an increase in p21(WAF1) and S arrest, indicating that PBD inhibitors also affected interphase before mitotic entry. Taken together, these data suggest that the PDB of Plk1 plays a role in S phase progression through interaction with other proteins, while its ATP-binding domain is important for regulating mitotic progression mediated by its catalytic activity involving consumption of ATP.

Calcium-sensing receptor and apoptosis in parathyroid hyperplasia of patients with secondary hyperparathyroidism.

OBJECTIVE: This retrospective study investigated the characteristics of secondary hyperparathyroidism (SHPT) by examining the presence of the calcium-sensing receptor (CaSR) and the rate of cell proliferation and apoptosis in parathyroid glands. METHODS: Eighteen diffuse and 57 nodular hyperplastic parathyroid glands from 24 patients with SHPT were compared with 14 primary adenomas and 33 normal parathyroid glands using immunohistochemical staining of CaSR and a marker of proliferative activity (Ki67 antigen). Apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling assay. RESULTS: The mean ± SE labelling index (LI) of CaSR (12.8% ± 1.5%) in nodular hyperplasia was significantly lower than that in normal parathyroid glands (26.8% ± 0.8%), whereas the mean ± SE LI of CaSR in diffuse hyperplasia was similar to that in normal parathyroid glands (23.3% ± 1.8%). The mean ± SE LI of Ki67 antigen was significantly higher in primary adenoma and nodular hyperplasia than in normal parathyroid glands. CONCLUSION: These results indicate that downregulation of CaSR, and a higher rate of proliferation over apoptosis, could contribute to the pathological progression of SHPT.

The anatomy of the external branch of the superior laryngeal nerve in Koreans.

BACKGROUND: Preservation of the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy is important because its injury may lead to frequent occurrence of vocal fatigue and the inability to perform superenergetic phonation. Most studies on the anatomy of EBSLN have been performed in Western countries and, thus, have some limitations in their application to Koreans. We explored the anatomy of EBSLNs using intraoperative neuromonitoring (IONM) in Korean adults. METHODS: Between August 2011 and December 2011, 50 patients underwent thyroidectomy at Korea University, Anam Hospital in Seoul, Korea. IONM was performed with the NIM response 3.0 system. RESULTS: Forty-two total thyroidectomies and eight lobectomies were performed with IONM and 92 EBSLNs were evaluated. Type I EBSLN was observed in 15 of the 92 nerves (16.3%), type IIa EBSLN was noted in 52 (56.5%) and type IIb EBSLN was noted in 25 (27.2%). Patients with types IIa and IIb were at higher risk of injuries and these types were more frequently observed (83.7%) compared with previous Western studies. We found that 35.9% of distal insertion sites of EBSLNs were located within 1cm of the center of the cricoid cartilage. CONCLUSION: Surgeons should pay close attention to preserving the EBSLN during thyroidectomy in Korean patients because their EBSLNs are more frequently located beneath the superior thyroid vessels.

A fraction of methylene chloride from Geum japonicum Thunberg inhibits tumor metastatic and angiogenic potential.

The plant Geum japonicum Thunberg (GjT) has been used as a diuretic in traditional medicine. Herein, we report that the GjT extract blocks both the spread of human umbilical vein endothelial cells (HUVECs) on matrigel and the migration of B16 cells. We used various assays to test for cell attachment, spreading, wound healing and angiogenesis. A reverse transcription-polymerase chain reaction (RT-PCR) and a mitogen-activated protein kinase (MAPK) assay were also carried out for the mechanistic study of GjT. Our results showed that a fraction of methylene chloride fraction from GjT inhibited B16 cells during cell attachment and migration and suppressed tube formation in a dose-dependent manner. An RT-PCR analysis showed that the methylene chloride extract decreased the mRNA expression of CD44 and TIMP-2. A Western blot analysis of the phosphorylation of MAPK kinases (ERK, JNK and p38) showed that the GjT fraction increased the expression of phospho-JNK, suggesting that GjT has the potential to alleviate metastatic and angiogenic activity, via a phospho-JNK signaling pathway.

Aqueous extract of the Helianthus annuus seed alleviates asthmatic symptoms in vivo.

Molecular inflammation is a pivotal process in various degenerative immune diseases, including asthma and atopic dermatitis. In this study, we examined the effects of Helianthus annuus seed (HAS) aqueous extract on an in vivo anti-asthmatic model. Ovalbumin-induced mice were orally administered the aqueous extract of Helianthus annuus seeds, and their lungs were assessed by hematoxylin and eosin staining. Moreover, the expression levels of IL-4/IL-13 cytokines and IgE were determined. HAS extract induced a decrease in CD4+ cell number, IL-4/IL-13 expression, and IgE secretion levels in the lungs. Our findings collectively suggest that the HAS extract has considerable potential in reducing the asthma-like symptoms induced by a mouse ovalbumin challenge model. However, further isolation and purification of the extract is required to determine the specific factor(s) responsible for its anti-asthmatic activity.

Anti-tumor activity of Gastrodia elata Blume is closely associated with a GTP-Ras-dependent pathway.

Gastrodia elata Blume (GEB) is an important medicinal plant in Korea. In order to confirm the anti-tumor activities of GEB extracts, we carried out various in vitro anti-tumor assays, including a wound assay and an invasion assay using an ethyl ether extract of GEB. The results showed that the GEB extract exhibits potent anti-tumor activity in vitro in a dose-dependent manner. The expression of CD44, cdc42, Timp-2 or RhoA mRNA did not change by GEB treatment, compared to that of the control. GTP-Ras, an active form of a G-coupled protein family, however, is associated with the anti-tumor activity of GEB extracts. We examined various molecular markers related to metastasis by reverse transcriptase-polymerase chain reaction with the extract of GEB-treated B16 cells. There was an increase in GTP-Ras expression by the Gastrodia elata Blume extract. Together, these results suggest that the Gastrodia elata Blume extract could have potential in alleviating tumorigenesis, by a GTP-Ras-dependent pathway; although the precise molecular mechanisms are still being examined.

Gastrodia elata Blume protects against stress-induced gastric mucosal lesions in mice.

Gastrodia elata Blume (GEB) is a traditional herbal plant that has been used in Asian countries for centuries as an anticonvulsant, analgesic, and also as a sedative for treating general paralysis, epilepsy, vertigo, and tetanus. Although numerous reports have addressed the effects of GEB against degenerative diseases, no previous study has examined the possible gastroprotective effects of GEB. Here, we examined the effects of pretreatment with GEB (0.02 ml/g, p.o.) in a mouse water immersion restraint (WIR) stress-induced gastric lesion model. Our results revealed that mice pretreated with GEB had significantly fewer gastric lesions than their respective controls. Moreover, GEB-treated mice showed significant decreases in serum and gastric nitric oxide (NO) levels to 50 and 28%, respectively. To examine one possible mechanism underlying this effect, we used reverse transcription-polymerase chain reaction (RT-PCR) to examine NOS mRNA expression in gastric lesion tissues. Our results revealed that the mRNA expression of inducible nitric oxide synthase (iNOS) was reduced by approximately 50% in GEB-pretreated mice versus the controls, whereas the mRNA expression levels of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) remained unchanged. These findings collectively suggest that GEB significantly protects the gastric mucosa against WIR-induced gastric damage, at least in part by decreasing NO levels via suppression of iNOS mRNA expression.

Dykellic acid inhibits cell migration and tube formation by RhoA-GTP expression.

Dykellic acid, a novel factor initially identified from the culture broth of Westerdykella multispora F50733, has been shown to inhibit matrix metalloprotease 9 activity, caspase-3 activity, B cell proliferation and LPS-induced IgM production, suggesting that this factor may have anti-cancer effects. In an effort to further address the possible anti-tumoral effects of dykellic acid, we used wound healing, invasion and RhoA-GTP assays to examine the effects of dykellic acid on cell migration, invasion and angiogenesis. Our results revealed that dykellic acid dose-dependently inhibits B16 cell migration and motility, and inhibits HUVEC tube formation. Western blot analysis of the active form of RhoA (RhoA-GTP) showed that dykellic acid treatment decreased the levels of RhoA-GTP. These findings collectively suggest that dykellic acid may have both anti-metastatic and anti-angiogenic acitivites, and provides the first evidence for the involvement of RhoA in dykellic acid-induced effects.

Effect of core-needle biopsy vs fine-needle aspiration on pathologic measurement of tumor size in breast cancer.

HYPOTHESIS: Core-needle biopsy (CNB) and fine-needle aspiration (FNA) play an important role in the initial diagnosis of breast cancer. However, CNB might alter the size of the tumor, which might subsequently change its pathologic stage and thus affect the decision about adjuvant chemotherapy. PATIENTS: Between January 2000 and May 2002, we studied 291 patients with invasive carcinoma lesion in a retrospective analysis. One hundred ninety-nine patients underwent ultrasonography-guided CNB. Ninety-two patients had FNA before surgical manipulation. MAIN OUTCOME MEASURES: The clinically measured tumor size using ultrasonography was compared with the pathologic tumor size in both the CNB and FNA groups. The difference in each group was determined and analyzed using a t test. The mean +/- SD preoperative ultrasonographically measured size in the CNB group was 2.09 +/- 1.06 cm and in the FNA group, 2.16 +/- 0.92 cm (no significant difference). The pathologic measurement of the lesion on surgical specimens revealed that the mean pathologic tumor size was 2.09 +/- 0.90 cm in the CNB group and 2.36 +/- 0.92 cm in the FNA group. The changes in size from preoperative measurements by ultrasonography to pathologic measurements on surgical specimens were greater in the CNB group (0.003 +/- 0.65 cm) than in the FNA group (0.20 +/- 0.39 cm; P = .001). CONCLUSIONS: Although the reduction in tumor size might be small with patients who undergo CNB, it must be considered when deciding adjuvant treatment, especially for tumor sizes on the "borderline" in establishing the indication for and the type of adjuvant treatment.