Phylogenetic analysis, morphological studies, element profiling, and muscarine detection reveal a new toxic Inosperma (Inocybaceae, Agaricales) species from tropical China

Tropical Asian collections of Inosperma are usually poisonous mushrooms that have caused many poisoning incidents. However, the species diversity and the toxic mechanisms of these Inosperma species are still unclear. In this study, we describe the discovery of Inosperma wuzhishanense sp. nov. from Wuzhishan City, Hainan Province, tropical China. The new species was identified based on morphological and multi-locus (ITS, nrLSU, and RPB2) phylogenetic analyses. The new species is characterized by its reddish-brown pileus, fibrillose stipes with finely protruding fibrils, rather crowded lamellae, smooth and ellipsoid basidiospores, and mostly clavate, thin-walled cheilocystidia. The new species is phylogenetically nested in the Old World tropical clade 2 and is sister to the tropical Indian taxa I. akirnum. Detailed descriptions, color photos of the new species, and comparisons with its closely related species are provided. Additionally, the muscarine content of the new species was analyzed by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). The muscarine contents ranged from 4,359.79 ± 83.87 mg/kg to 7,114.03 ± 76.55 mg/kg, 2,748.37 ± 106.85 mg/kg to 4,491.35 ± 467.21 mg/kg, and 2,301.36 ± 83.52 mg/kg to 2,775.90 ± 205.624 mg/kg in the stipe, pileus, and lamellae, respectively. The elemental composition and concentration were determined using inductively coupled plasma-mass spectrometry (ICP-MS). A total of 24 elements were detected. Among the heavy metals detected, arsenic showed the highest level of toxicity with a concentration of 36.76 ± 0.43 mg/kg.

[Cytopathological characterization of ascites for the diagnosis of serous ovarian carcinoma]

Objective: To investigate the cytomorphological and immunocytochemical features of tumor cells in the ascites of ovarian plasmacytoma (SOC). Methods: Specimens of serous cavity effusions were collected from 61 tumor patients admitted to the Affiliated Wuxi People's Hospital of Nanjing Medical University from January 2015 to July 2021, including ascites from 32 SOC, 10 gastrointestinal adenocarcinomas, 5 pancreatic ductal adenocarcinomas, 6 lung adenocarcinomas, 4 benign mesothelial hyperplasia and 1 malignant mesothelioma patients, pleural effusions from 2 malignant mesothelioma patients and pericardial effusion from 1 malignant mesothelioma. Serous cavity effusion samples of all patients were collected, conventional smears were made through centrifugation, and cell paraffin blocks were made through centrifugation of remaining effusion samples. Conventional HE staining and immunocytochemical staining were applied to observe and summarize cytomorphological characteristics and immunocytochemical characteristics. The levels of serum tumor markers carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were detected. Results: Of the 32 SOC patients, 5 had low-grade serous ovarian carcinoma (LGSOC) and 27 had high-grade serous ovarian carcinoma (HGSOC). 29 (90.6%) SOC patients had elevated serum CA125, but the difference was not statistically significant between them and patients with non-ovarian primary lesions included in the study (P>0.05); The serum CEA was positive in 9 patients with gastrointestinal adenocarcinoma and 5 patients with lung adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.001); The serum CA19-9 was positive in 5 patients with gastrointestinal adenocarcinoma and 5 patients with pancreatic ductal adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.05). The serum CA125, CEA and CA19-9 were within the normal range in 4 patients with benign mesothelial hyperplasia. LGSOC tumor cells were less heterogeneous and aggregated into small clusters or papillary pattern, and psammoma bodies could be observed in some LGSOC cases. The background cells were fewer and lymphocytes were predominant; the papillary structure was more obvious after making cell wax blocks. HGSOC tumor cells were highly heterogeneous, with significantly enlarged nuclei and varying sizes, which could be more than 3-fold different, and nucleoli and nuclear schizophrenia could be observed in some cases; tumor cells were mostly clustered into nested clusters, papillae and prune shapes; there were more background cells, mainly histiocytes. Immunocytochemical staining showed that AE1/AE3, CK7, PAX-8, CA125, and WT1 were diffusely positively expressed in 32 SOC cases. P53 was focally positive in all 5 LGSOCs, diffusely positive in 23 HGSOCs, and negative in the other 4 HGSOCs. Most of adenocarcinomas of the gastrointestinal tract and lung had a history of surgery, and tumor cells of pancreatic ductal adenocarcinoma tend to form small cell nests. Immunocytochemistry can assist in the differential diagnosis of mesothelial-derived lesions with characteristic "open window" phenomenon. Conclusion: Combining the clinical manifestations of the patient, the morphological characteristics of the cells in the smear and cell block of the ascites can provide important clues for the diagnosis of SOC, and the immunocytochemical tests can further improve the accuracy of the diagnosis.

[Application of pathological feature clustering in oral pathology teaching]

To propose a new student-guided teaching method, in which students carried out the clustering of different diseases with the same pathological characteristics, and differentiated diagnosis of these diseases. This method was named pathological feature clustering (PFC). Seventy-seven undergraduates of School of Stomatology, Wuhan University were enrolled. Stratified random sampling method was adopted to divide the students into 4 groups with 18-20 students in each group. Each group of students selected a disease from the following four topics as the theme and summarize the histological characteristics of the disease: ①oral mucosal disease;②odontogenic tumors and tumor-like lesions, oral and maxillofacial cysts; ③salivary gland diseases;④epithelial-derived tumors and tumor-like lesions (referred to as topics 1, 2, 3, and 4, respectively). When discussing a specific type of disease, the group which select the topic was the summary group (SG), and the other groups were the non-summary group (NSG). After summarizing, students shared the summary results through PPTs, and teachers made comments and supplements. The teaching effect was evaluated by comparing the results of the pre-class test and the final examination. Students' acceptance of PFC teaching method was evaluated through a questionnaire, which included 8 objective questions and 1 subjective question. Likert-scale was used to design the questionnaire, with 1 to 5 points for each question. Students rated each question according to their own situation. Differences among groups were compared by Mann-Whitney U nonparametric test. The pre-class test results showed that the scores of students in SG group in subjects 1, 2, 3 [(5.6±0.8), 5.0(1.0) and (2.9±1.0) points for subjects 1, 2 and 3, respectively] were higher than those in NSG group [(5.1±1.0), 4.0(2.5) and 1.5(2.5) points] (U=402.50, P=0.047; U=392.00, P=0.026; U=295.00, P=0.003). The final examination results showed that there was no significant difference between the scores of the SG group and the NSG group in subjects 1, 2, 3 and 4 (P>0.05). These results showed that the differences between SG and NSG groups were reduced after the summarizing and share between groups, further demonstrating the effectiveness of the PFC teaching method. The results of questionnaire showed that 81.8%(63/77) students were completely satisfied with PFC teaching method, 13.0%(10/77) students were satisfied and 5.2%(4/77) students were basically satisfied. According to the feedback of Likert scale objective evaluation questionnaire, the mean score of each question ranged from 4.19 to 4.77, indicating that students believed that PFC teaching method had a positive impact on the learning of oral pathology. The PFC teaching method proposed in this study could improve the ability of pathological differential diagnosis of undergraduates.

Insights into the mechanisms of triptolide nephrotoxicity through network pharmacology-based analysis and RNA-seq

INTRODUCTION

Triptolide (TPL) is a promising plant-derived compound for clinical therapy of multiple human diseases; however, its application was limited considering its toxicity.

METHODS

To explore the underlying molecular mechanism of TPL nephrotoxicity, a network pharmacology based approach was utilized to predict candidate targets related with TPL toxicity, followed by deep RNA-seq analysis to characterize the features of three transcriptional elements include protein coding genes (PCGs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) as well as their associations with nephrotoxicity in rats with TPL treatment.

RESULTS & DISCUSSION

Although the deeper mechanisms of TPL nephrotoxcity remain further exploration, our results suggested that c-Jun is a potential target of TPL and Per1 related circadian rhythm signaling is involved in TPL induced renal toxicity.

Collagen IV and Podocyte-Related Gene Variants in Patients with Concurrent IgA Nephropathy and Thin Basement Membrane Nephropathy

INTRODUCTION

IgA nephropathy is the most common primary glomerulonephritis among adults in clinic. Thin basement membrane nephropathy is often underestimated or even omitted if it coincides with IgA nephropathy. Therefore, it is necessary to study the epidemiological, clinical, and molecular characteristics of the concurrence of this entity.

METHODS

Eight patients with concurrent IgA nephropathy and thin basement membrane nephropathy (IgA-T) were retrospectively analyzed based on their clinicopathological characteristics. Genetic analysis was performed using whole-exome sequencing and Sanger's sequencing. Data of the patients with IgA nephropathy and normal basement membrane (IgA-N) and variants in the local in-house database were used as controls. All candidate variants were assessed in silico.

RESULTS

The clinical manifestations of patients with IgA-T were hematuria, proteinuria, and renal insufficiency. Histopathological analysis showed mild mesangial hyperplasia, focal segmental glomerulosclerosis, podocyte activation, and foot process fusion. Crescent was rarely seen. COL4A and/or podocyte cytoskeleton and mitochondria-related gene variants were detected in seven IgA-T patients. Three patients exhibited pathogenic variants of COL4A, including a new variant. All IgA-T and one IgA-N patient possessed ITGB4 and/or PLEC variants, but there was no corresponding genotype-phenotype relationship. Six patients possessed other podocyte cytoskeleton and mitochondria-related gene variants such as NPHS2, SRGAP1, MYO1E, MYO1C, WT1, and COQ9, which were first reported in patients with IgA-T and were not in controls. Altogether, there were no significant differences in the degrees of proteinuria, serum creatinine, and eGFR during the follow-up period of 5-10 years, but there was a significant difference in the degree of proteinuria between IgA-T patients with podocyte-related gene variants and IgA-N patients. In the IgA-T group, patients with podocyte-related gene variants seemed predisposed to progress than patients without those variants, with higher proteinuria and serum creatinine and reduced eGFR.

CONCLUSION

Concurrent thin basement membrane nephropathy and/or heterozygous COL4A gene pathogenic variants do not necessarily predict the short-term progress of sporadic IgA nephropathy in adults. Predisposition factors for this disease progression should be considered for detecting the variants of COL4A and podocyte cytoskeleton and mitochondria-related genes simultaneously, which also manifests the complexity and heterogeneity of IgA nephropathy with concurrent thin basement membrane nephropathy.

[Epstein-Barr virus infection-related post-transplant lymphoproliferative disorders in transplanted lung: a clinicopathological analysis]

Objective: To investigate the clinicpathological characteristics of post-transplant lymphoproliferative disorders (PTLD) in transplanted lung, and to improve its diagnosis and treatment. Methods: The clinicopathological characteristics of PTLD in three transplanted lungs were evaluated at Wuxi People's Hospital Affiliated to Nanjing Medical University from 2014 to 2019. HE, immunohistochemical staining and in situ hybridization were performed. The relevant literature of PTLD was reviewed. Results: All three patients had chronic obstructive pulmonary disease (COPD) before lung transplantation. After receiving both lung transplants, they were all treated with anti-rejection drugs tacrolimus or mycophenolate mofetil, and combined with antiviral and/or rituximab. The time from transplantation to diagnosis of PTLD was four years, seven months, and five months, respectively. Two patients died one month and five months after initial diagnosis, and one patient was alive with no disease after one year. Histologically, all cases were monomorphic B-cell PTLD (diffuse large B-cell lymphoma, unspecified), and the tumor cells were positive for Epstein-Barr virus by in situ hybridization; one of the late-onset patients had herpes simplex virus infection. Conclusions: PTLD in the post-transplant lung tissue shows unique morphology and clinical characteristics, and is closely related to Epstein-Barr virus infection. Patients who receive lung transplantation due to COPD are more susceptible to develop PTLD, while late-onset ones occur more commonly in the hilum of lungs, and the prognosis is relatively poor.

Sarcomatoid intrahepatic cholangiocarcinoma mimicking liver abscess: A case report

BACKGROUND

Sarcomatoid intrahepatic cholangiocarcinoma (SICC) is an extremely rare and highly invasive malignant tumor of the liver. To our knowledge, the imaging findings of sarcomatous cholangiocarcinoma have been rarely reported; and radiological features of this tumor mimicking liver abscess have not yet been reported.

CASE SUMMARY

We present a case of SICC mimicking liver abscess. The patient, a 43-year-old male, complained of repeated upper right abdominal discomfort and intermittent distension over a period of one month. Radiology examination revealed a huge focal lesion in the right liver. The lesion was hypointense on computed tomography with honeycomb enhancement surrounded by enhanced peripheral areas. It showed a hypo-signal on non-contrast T1-weighted images and a hyper-signal on non-contrast T2-weighted images. Radiologists diagnosed the lesion as an atypical liver abscess. The patient underwent a hepatectomy. After surgery, he survived another 2.5 mo before passing away. A search of PubMed and Google revealed 43 non-repeated cases of SICC reported in 20 published studies. The following is a short review in order to improve the diagnostic and therapeutic skills in cases of SICC.

CONCLUSION

This report presents the clinical and radiological features of SICC and imaging features which showed hypovascularity and progressive enhancement. SICC can present as a multilocular cyst on radiological images and it is necessary to distinguish this lesion from an atypical abscess. Simple surgical treatment is not the best treatment option for this disease.

Characterization of breast lesions using diffusion kurtosis model-based imaging: An initial experience

OBJECTIVE

To investigate the characterization of breast lesions using diffusion kurtosis model-based imaging.

METHODS

This prospective study included 120 consecutive patients underwent preoperative DCE-MRI examinations and multi-b-value diffusion-weighted imaging (DWI). Among them, 88 malignant lesions and 44 benign lesions were detected, 56 normal fibroglandular breast tissue were selected as normal control. Conventional apparent diffusion coefficient (ADC), DKI-based parameters mean kurtosis (MK) and mean diffusivity (MD) were analyzed by lesions types and histological subtypes using one-way ANOVA and receiver operating characteristic (ROC) curve.

RESULTS

(1) The malignant group showed significantly lower ADC and MD (1.07±0.32×10-3 mm2/s and 1.30±0.40×10-3 mm2/s, respectively) and higher MK (0.87±0.18) than those in the benign group (1.29±0.26×10-3 mm2/s, 1.62±0.31×10-3 mm2/s and 0.67±0.18) and control group (1.67±0.33×10-3 mm2/s, 2.24±0.28×10-3 mm2/s and 0.52±0.08) with all P < 0.001. (2) Areas under ROC curve (AUC) for diagnosing malignant lesions were 0.936 for MD, 0.911 for MK and 0.897 for ADC, respectively. AUC for MD was significantly higher than that for ADC (P = 0.015). The optimal cut-off value, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were as follow: ADC = 1.18×10-3mm2/s, 78.3%, 93.2%, 81.2%, 81.6%, 81.4%; MD = 1.48×10-3mm2/s, 82.2%, 98.3%, 84.4%, 87.8%, 86.2%; MK = 0.78, 91.5%, 85.3%, 89.0%, 85.8%, 87.2%. (3) Invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS) and mucinous adenocarcinoma also showed significant differences among ADC, MD and MK (with P < 0.05).

CONCLUSIONS

MR-DKI parameters enable to improve breast lesion characterization and have diagnostic potential applying to different pathological subtypes of breast cancers.

Undifferentiated myxoid lipoblastoma with PLAG1 gene rearrangement in infant

OBJECTIVES

To analyze the clinicopathologic feature, diagnosis and differential diagnosis of undifferentiated myxoid lipoblastoma in infant.

METHODS

The study included 2 cases of undifferentiated myxoid lipoblastoma in infant according to the molecular genetic diagnosis. The relevant clinicopathologic feature was investigated.

RESULTS

We describe 2 cases of undifferentiated myxoid lipoblastoma in infant. The both large circumscribed masses are located in deep soft tissue. Unlike most lipoblastoma, lobulated appearance was not obvious in one case and completely absent in another. The both cases presented prominent myxoid change with a plexiform vascular pattern. There were some spindle-shaped or stellate mesenchymal cells, while no any mature adipocytes. The initial suggestion of case 1 was myxoid liposarcoma, and case 2 was aggressive angiomyxoma. However, few S-100 positive lipoblasts suggested the origin of the tumor. FISH analysis using a PLAG1 break apart probe confirmed a PLAG1 rearrangment. The final diagnosis was undifferentiated myxoid lipoblastoma.

CONCLUSIONS

The undifferentiated myxoid lipoblastoma is a very rare tumor in infant. Histologically, prominent myxoid change, a plexiform vascular pattern and lacking of mature adipocytes make it indistinguishable from myxoid liposarcoma, PMMTI and aggressive angiomyxoma. The S-100 positive lipoblasts and genetic rearrangement of PLAG1 helps in confirming the diagnosis. Even if there were no mature adipocytes, myxoid lipoblastoma was still a diagnosis that can not be ignored in myxoid tumors in children.

[Myxoid lipoblastoma:a clinicopathological study of four cases]

Objective: To study clinicopathological features,diagnosis and differential diagnosis of myxoid lipoblastoma. Methods: Four cases of myxoid lipoblastoma, from 2010 to 2017 at Wuxi People's Hospital of Nanjing Medical University, the Affiliated Hospital of Xuzhou Medical University and Binhai People's Hospital, were studied by clinicopathological analysis, immunohistochemistry and in situ hybridization along with a literature review. Results: The age of the patients ranged from 1 to 6 years. Histologically, all tumors had thin fibrous capsule and irregular lobules separated by fibrous septa. The individual lobules consisted of myxoid stroma,prominent plexiform capillary network and stellate or spindle mesenchymal cells. Lipoblasts (S-100 positive) and mature adipocytes varies among different lobules. FISH revealed PLAG1 disruption in all 4 cases. MDM2 or CHOP alterations were not detected. None of the patients had tumor recurrence upon follow up from 12 to 80 months. Conclusions: Myxoid lipoblastoma is a very rare tumor, usually in the first 5 years of life. The clinical features of myxoid lipoblastoma and lipoblastoma are similar, while myxoid lipoblastoma has prominent myxoid change, a plexiform vascular pattern and rare mature fat cells. The patient age,S-100 positive lipoblasts and cytogenetic alteration are the key diagnostic features.

Evaluation of the MiSeq FGx system for use in forensic casework

Capillary electrophoresis (CE) is widely used in forensic genetics to study short tandem repeats (STRs). Recently, next-generation sequencing (NGS) platforms have facilitated the development of new strategies for forensic DNA typing. Several studies have shown that NGS successfully analyzes challenging samples. However, because NGS is complicated and time-consuming, it remains unclear whether NGS platforms offer significant advantages over CE for all forensic cases. Here, the MiSeq FGx system was used to test some cases that had previously been analyzed using CE. These cases included paternity test cases in which some samples exhibited locus inconsistencies; samples with off-ladder (OL) alleles; samples with triallelic patterns; and samples with amelogenin test abnormalities. The results generated by MiSeq FGx were compared to those previously generated by CE. The MiSeq FGx and CE results were consistent with the exception of three samples, where inconsistencies were observed at the Penta D locus. For all three incongruent samples, the MiSeq FGx results were correct. Sequence analysis indicated that, in two cases, mismatches were due to undetected alleles rather than mutations. In two additional cases, mutation sources were identified, and in a fifth case, mutation step size was reconsidered. MiSeq FGx was used to identify OL alleles and samples with amelogenin test abnormalities. For cases where verification was required via CE analysis, the simultaneous NGS amplification of several types of multiple genetic markers improved testing efficiency. In addition, we identified additional sequence variants at autosomal, Y chromosomal, and X chromosomal STR loci in the Han Chinese population from northern China. Our results will be useful for future forensic analyses of STR genotypes in Chinese populations. It is likely that NGS would be more widely used in forensic genetics if costs and procedure complexity were reduced.

Electro-optically spectrum narrowed, multiline intracavity optical parametric oscillators

We report on the first building of an active spectral narrowing mechanism in a pulsed, multiline optical parametric oscillator (OPO) based on a novel aperiodically poled lithium niobate (APPLN) device constructed using the aperiodic optical superlattice technique. The APPLN device functions simultaneously in the system as a multi-channel optical parametric down converter (OPDC) and an electro-optic (EO) gain spectral filter working on the corresponding (multiple) signal bands. When the APPLN OPO was installed in a diode pumped Nd:YVO₄ laser system, highly narrowed dual-wavelength signal lines (at 1540 and 1550 nm) were observed at the output of the system through EO control of the APPLN. Correspondingly, an enhancement of the power spectral density of the source by a factor of ~7.8 with respect to the system operated in passive mode was found.

Association of leptin, visfatin, apelin, resistin and adiponectin with clear cell renal cell carcinoma

Although an association between obesity and the occurrence of renal cell carcinoma (RCC) has been identified, the mechanism by which obesity functions to increase this risk of cancer remains unclear. Leptin, visfatin, apelin, resistin and adiponectin are peptide hormones secreted by adipocytes; it is considered that these may affect RCC development by exerting effects on proliferation, cell growth and inflammation. The aim of the present study was to investigate the association between the aforementioned adipokine genes and clear cell RCC (CC-RCC). The GSE6344 dataset was downloaded from the Gene Expression Omnibus database, and the relative expression levels of the adipokine genes were analyzed. To verify the results of the mRNA microarray, 77 paired samples of CC-RCC and corresponding adjacent normal tissue were allocated into two groups. The extraction of total RNA was conducted, and the mRNA expression of adipokine genes was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The data from the GSE6344 dataset indicated that the expression of visfatin and apelin was upregulated (P<0.0001 and P<0.01, respectively), and adiponectin was downregulated (P<0.001) in the CC-RCC tissues compared with the adjacent normal tissues. The data from RT-qPCR demonstrated that visfatin and resistin gene expression was increased (P<0.01 and P<0.05, respectively) in the CC-RCC tissues. Furthermore, the mRNA expression level of leptin and adiponectin in the adjacent normal tissue was higher than those in the cancer tissue (P<0.01). The current study verifies that visfatin and adiponectin are associated with an increased risk of CC-RCC, which presents further insights into the molecular mechanisms of CC-RCC tumorigenesis.

High-resolution Melting PCR Analysis for Genotyping Lys109Arg and Gln223Arg in Patients with Renal Cell Carcinoma

Although several studies have documented the role of leptin receptor gene polymorphisms in cancers, the association between leptin receptor gene polymorphisms and renal cell carcinoma (RCC) remains unknown. The aim of this study was to develop a high-resolution melting (HRM) approach for genotyping single nucleotide polymorphisms of leptin receptor gene on the LightCycler 480, and to explore the relation between polymorphisms of the leptin receptor gene and RCC. The study population consisted of 83 patients with renal cell carcinoma and 161 healthy control subjects. The Lys109Arg (A/G) and Gln223Arg (A/G) polymorphisms of leptin receptor gene were examined with HRM assay. Direct DNA sequencing and PCR-restriction fragment length polymorphisms were used as a reference method for genotyping Lys109Arg and Gln223Arg, respectively. Three genotypes of Lys109Arg or Gln223Arg were clearly distinguishable from the melting curve shapes with HRM assay. The data also showed the results of the direct DNA sequencing or PCR-restriction fragment length polymorphisms analysis were in complete concordance to genotyping results obtained by HRM (kappa=1.0). In addition, the data showed the G-G haplotype frequency was higher (p<0.05), and that the A-G (p<0.001) and G-A (p<0.01) haplotypes frequencies were lower in the RCC than controls. We developed a rapid, low cost, high-throughput and reliable single-tube technology for genotyping Lys109Arg and Gln223Arg polymorphisms. In addition, our data suggest that Lys109Arg and Gln223Arg gene polymorphisms are associated with RCC in Chinese Han studied population.

Association of leptin receptor Lys109Arg and Gln223Arg polymorphisms with increased risk of clear cell renal cell carcinoma

BACKGROUND

Although roles of genetic polymorphisms of leptin receptor (LEPR) gene in several cancers have been documented, the association between polymorphisms of LEPR and clear cell renal cell carcinoma (CC-RCC) remains unknown. The aim of this study was to explore any relation.

MATERIALS AND METHODS

The study population consisted of 77 patients with CC-RCC and 161 healthy control subjects. Polymorphism analyses of Lys109Arg and Gln223Arg were performed by direct DNA sequencing and PCR-restriction fragment length polymorphism approaches respectively.

RESULTS

Comparisons of allelic and genotypic frequencies in Lys109Arg and Gln223Arg showed no significant difference between the cases and controls. However, when evaluating the combined genotype of Lys109Arg and Gln223Arg, risk with GG/GG was increased (OR=1.85, 95%CI=1.04-3.30) and with GA/GG or GG/GA was decreased (OR=0.07, 95%CI=0.01-0.54; OR and 95%CI of the latter could not be calculated for a value of zero) . Furthermore, the G-G haplotype frequency of Lys109Arg and Gln223Arg in the cases was higher (OR=1.68; 95%CI=1.02-2.76). In contrast, the A-G and G-A haplotype frequencies in the cases were lower than those in the controls (OR=0.06; 95%CI=0.01 to 0.47; OR and 95%CI of the latter could not be calculated for a value of zero). In addition, the Lys109Arg A allele was in LD with the Gln223Arg A allele (d'=0.9399) in the CC-RCC subjects, but not in the controls.

CONCLUSIONS

Our data suggest that the GG/GG combined genotype and G-G haplotype of Lys109Arg and Gln223Arg can act as evaluating factors for CC-RCC risk.

Decreased analgesic effect of morphine, but not buprenorphine, in patients with advanced P-glycoprotein(+) cancers

BACKGROUND

P-glycoprotein (P-gp) is expressed on the blood-brain barrier (BBB) and acts as a transporter regulating the analgesic effect of morphine. The P-gp is also expressed by different types of tumors. The aim of this study was to determine the potential association of the P-gp expression in malignant tumors with analgesic effects in patients.

METHODS

The P-gp expression in 120 malignant tumors was examined by immunohistochemistry. The analgesic responses of individual patients to morphine and buprenorphine (BNP) were evaluated by visual analog scale (VAS). The levels of plasma morphine and BNP were determined by HPLC.

RESULTS

We found that there was no significant difference in the values of VAS between patients with P-gp(+) and P-gp(-) malignant tumors in responses to 0.000025 g x kg(-2) of BNP administered by patient-controlled intravenous analgesia (PCIA), accompanied by similar levels of plasma BNP in those patients. In contrast, the values of VAS in response to 0.00075 g x kg(-2) of morphine in patients with P-gp(+) tumors were significantly greater than those in the patients with P-gp(-) tumors, although similar levels of plasma morphine were detected in both groups of patients. Furthermore, treatment with a higher dose (0.0011 g x kg(-2)) of morphine effectively controlled pain in those with P-gp(+) tumors.

CONCLUSION

Our data indicated that patients with P-gp(+) tumors required a higher dose of morphine to achieve an analgesic effect and that the P-gp expression in tumors may be valuable for predicting the analgesic responses of patients with severe pain to morphine.

Analysis of flicker noise for improved data retention characteristics in silicon-oxide-high-k-oxide-silicon flash memory using N2 implantation

In this paper, we fabricate planar-type Silicon-Oxide-High-k-Oxide-Silicon (SOHOS) and the planar-type SOHOS devices with N2 implantation of 3 x 10(15) dose in a tunneling oxide to determine the impact of N2 implantation in the tunneling oxide of a memory device. The N2 implantation device has better retention characteristics than the device with no implantation. In order establish the correlation between N2 implantation and retention characteristic improvement, the low frequency noise (1/f noise) characteristic is investigated. The normalized drain current noise (S(ID)/I(D)2) level of the N2 implantation device is higher than that of the device with no implantation, which means that N2 implantation causes more trap formation near the interface. Considering that N2 implantation does not affect the DC transfer characteristics, such as mobility and sub-threshold slope, this finding indicates that the increase in the 1/f noise level is due to oxide traps rather than to interface traps. Therefore, the retention characteristic improvement in the N2 implantation device can be explained by the generation of higher number of oxide traps and an increase in the potential barrier blocking the leakage path in the tunneling oxide.

Electrical characteristic analysis using low-frequency noise in low-temperature polysilicon thin film transistors

This study carried out an electrical characteristic analysis using low-frequency noise (LFN) in top gate p-type low-temperature polysilicon thin film transistors (LTPS TFTs) with different active layer thicknesses between 40 nm and 80 nm. The transfer characteristic curves show that the 40-nm device has better electrical characteristics compared with the 80-nm device. The carrier number fluctuation, with and without correlated mobility fluctuation model in both devices, has modeled well the measured noise. On the other hand, the trap density and coulomb scattering in the 40-nm device are smaller compared with the 80-nm device. To confirm the effectiveness of the LFN noise analysis, the trap densities at a grain boundary are extracted using in both devices the similar methods of Proano et al. and Levinson et al. That is, coulomb scattering, caused by the trapped charges at or near the interface, has a greater effect on the device with inferior electrical properties. Based on the LFN and the quantitative analysis of the trap density at a grain boundary, the interface traps between the active layer and the gate insulator can explain the devices' electrical degradation.

Hierarchically structured carbon-based composites: Design, synthesis and their application in electrochemical capacitors

This feature article provides an overview of the recent research progress on the hierarchically structured carbon-based composites for electrochemical capacitors. The basic principles of electrochemical capacitors, and the design, construction and performance of hierarchically structured carbon-based composites electrode materials with good ions and electron transportation and large specific surface area are discussed. The trend of future development of high-power and large-energy electrochemical capacitors is proposed.

Observation of two new N* peaks in J/psi-->ppi-n and ppi+n decays

The decay J/psi-->NNpi provides an effective isospin 1/2 filter for the piN system due to isospin conservation. Using 58x10(6) J/psi decays collected with the Beijing Electromagnetic Spectrometer at the Beijing Electron Positron Collider, more than 100 thousand J/psi-->ppi-n+c.c. events are obtained. Besides the two well-known N* peaks at around 1500 MeV/c2 and 1670 MeV/c2, there are two new, clear N* peaks in the ppi invariant mass spectrum around 1360 MeV/c2 and 2030 MeV/c2 with statistical significance of 11sigma and 13sigma, respectively. We identify these as the first direct observation of the N*(1440) peak and a long-sought missing N* peak above 2 GeV/c2 in the piN invariant mass spectrum.

The inhibitory effects of roflumilast on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells are mediated by heme oxygenase-1 and its product carbon monoxide

OBJECTIVES

Heme oxygenase-1 (HO-1) is an enzyme that degrades heme into biliverdin, free iron, and carbon monoxide (CO). This enzyme is known to have cytoprotective and anti-inflammatory effects. In this study, we investigated whether roflumilast, a newly developed specific phosphodiesterase 4 (PDE4) inhibitor, mediates some of its anti-inflammatory effects by blocking nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) via the induction of HO-1 expression in macrophages.

METHODS

The expression of iNOS and HO-1 was analyzed by western blot analysis. The production of NO and TNF-alpha was assayed by Greiss and ELISA, respectively.

RESULTS

Roflumilast markedly suppressed LPS-induced NO and TNF-alpha production and these phenomena were correlated with the induction of HO-1 protein levels. Moreover, the inhibitory effects of roflumilast on NO production were abrogated by a HO-1 inhibitor and a CO scavenger. Tricarbonyldichlrororuthenium(II) dimer, a CO releasing molecule significantly suppressed NO production.

CONCLUSIONS

These results suggested that roflumilast exerts its anti-inflammatory effects in macrophages through a novel mechanism that involves the action of HO-1 and its product, CO.

Fully dispersion-compensated approximately 500 fs pulse transmission over 50 km single-mode fiber

We demonstrate essentially distortionless 50 km fiber transmission for approximately 500 fs pulses, using dispersion-compensating fiber and a programmable pulse shaper as a spectral phase equalizer. This distance is approximately five times longer than previously achieved at similar pulse widths.

Observation of a threshold enhancement in the plambda invariant-mass spectrum

An enhancement near the m(p)+M(Lambda) mass threshold is observed in the combined pLambda and pLambda invariant-mass spectrum from J/psi-->pK(-)Lambda;+c.c. decays. It can be fit with an S-wave Breit-Wigner resonance with a mass m=2075+/-12(stat)+/-5(syst) MeV and a width of Gamma=90+/-35(stat)+/-9(syst) MeV; it can also be fit with a P-wave Breit-Wigner resonance. Evidence for a similar enhancement is also observed in psi(')-->pK(-)Lambda;+c.c. decays. The analysis is based on samples of 5.8x10(7)J/psi and 1.4x10(7)psi(') decays accumulated in the BES II detector at the Beijing Electron-Positron Collider.

Observation of the decay psi(2S)-->K0SK0L

The decay psi(2S)-->K(0)(S)K(0)(L) is observed using psi(2S) data collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider; the branching fraction is determined to be B(psi(2S)-->K(0)(S)K(0)(L))=(5.24+/-0.47+/-0.48)x10(-5). Compared with J/psi-->K(0)(S)K(0)(L), the psi(2S) branching fraction is enhanced relative to the prediction of the perturbative QCD "12%" rule. The result, together with the branching fractions of psi(2S) decays to other pseudoscalar meson pairs (pi(+)pi(-) and K+K-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

[Impact of AFP promoter on the expressions of GFP in tumor cells]

OBJECTIVE

To study the impact of AFP 5'flanking promoter (enhancer) on the expression of GFP in hepatocarcinoma cell.

METHODS

Green Fluorescent Protein (GFP) reporter gene expression plasmid pcDNA3-GFP-AFP-w under the direction of AFP 5' flanking promoter (enhancer) was constructed by recombinant DNA technology and confirmed by restriction analyses. pcDNA3-GFP-AFP-w, pcDNA3-GFP and pcDNA3 were transfected into Hela and Bel7402 cells by lipofectin and selected by G418 respectively, after amplification of the positive cell clones, expression of GFP was detected by Western blotting and quantitatively analysed by GEL Doc 2000 digital image systems.

RESULTS

The expression of GFP was lower in Bel-GFP-AFP-w than in Bel-GFP but was significantly higher than in Hela-GFP-AFP-w.

CONCLUSION

GFP reporter gene plasmid pcDNA3-GFP-AFP-w under the direction of the 3.1 kb AFP 5'flanking promoter (enhancer) can be expressed in HCC Bel7402 cell definitely and specifically.

Suppression of proline-directed protein kinase F(A) potentiates apoptotic induction and greatly enhances chemosensitivity in human acute lymphoblastic leukemia cells

BACKGROUND

Previously, the authors reported that specific antisense suppression of overexpressed proline-directed protein kinase (PDPK) F(A) enhances the chemosensitivity of various clinical anticancer drugs up to > 100-fold in human prostate carcinoma cells, suggesting an association of PDPK F(A) with drug resistance in human malignancies.

METHODS

In this report, by using a similar approach, the authors demonstrate further that the suppression of PDPK F(A) enhances even more dramatically the chemosensitivity of clinically used anticancer drugs in various types of human acute lymphoblastic leukemia (ALL) cells.

RESULTS

Compared with parental and control transfected cells, transduced ALL cells (both Jurkat and CCRF-CEM cells) with low levels of PDPK F(A) displayed an enhanced sensitivity to vincristine, vinblastine, paclitaxel, methotrexate, doxorubicin, and daunorubicin. Estimation of the 50% inhibitory concentration (IC(50)) index further revealed that the transduced cells displayed up to > 3000-fold drug sensitivity, and there was a correlation between suppressed levels of PDPK F(A) and drug sensitivity. A mechanistic study further revealed that the enhanced chemosensitivity in transduced ALL cells was due mainly to the potentiation of apoptotic induction.

CONCLUSIONS

Taken together, the results demonstrate that the suppression of overexpressed PDPK F(A) greatly enhances the chemosensitivity of various clinical anticancer drugs in both types of human ALL cells, providing initial evidence for an important role of this PDPK in controlling multidrug resistance of ALL.

Lead treatment in vitro at early developmental stage of bone marrow-derived macrophages enhances NO production through IL-1beta and IL-6 but not TNF-alpha

Lead (Pb(2+)) is known to decrease or block nitric oxide (NO) production by mature macrophages (mphi). Bone marrow cells were treated with various doses of lead in vitro and the morphological and functional changes were observed. Bone marrow cells were treated with various doses of lead (1, 10, 20 and 50 microM) at the start of culture with mphi growth factor (CSF-1), and after 6-7 days of culture, the resultant mphi (bone marrow-derived mphi, BMDM) showed decreased NO production. Unexpectedly, BMDM from the lowest does of lead treatment (1.0 microM) showed increased NO production. The increased NO production was due to increased expression of the iNOS gene and concurrent enhanced transcript levels of proinflammatory cytokines such as IL-1beta and IL-6, but not TNF-alpha. Lead treatment on mature BMDM showed decreased NO production in a dose-dependent manner. These results suggest that a low dose of lead affects developmental characteristics of BMDM through different proinflammatory cytokines, and the lead effects on precursor cells of mphi and mature mphi are different.

Suppression of proline-directed protein kinase F(A) systemically inhibits the growth of human acute leukemia cells

Initial studies revealed that proline-directed protein kinase F(A) (PDPK F(A)) was overexpressed in various cancerous tissues relative to normal controls. However, the functional role of overexpressed PDPK F(A) in cancer remains to be established. In this report, we explore the potential role of PDPK F(A) in leukemia cell growth by investigating the effects of partial inhibition of this kinase on human acute promyelocytic leukemia (HL-60) and acute lymphoblastic leukemia (Jurkat) cells. Cloning of PDPK F(A) cDNA and its recombinant antisense expression vector and antibody were successfully developed. Several stable antisense clones of HL-60 and Jurkat cells were subcloned, which expressed a low level of PDPK F(A) when compared with the control-transfected clone in immunoblot analysis. Moreover, these antisense clones potently inhibited cell growth, clonogenic growth in soft agar and serum-independent growth. The results taken together demonstrate that suppression of PDPK F(A) is able to interfere with the growth of HL-60 and Jurkat cells, suggesting an essential role of this PDPK in human acute leukemia cell growth.

Apoptotic signalling cascade in photosensitized human epidermal carcinoma A431 cells: involvement of singlet oxygen, c-Jun N-terminal kinase, caspase-3 and p21-activated kinase 2

Photodynamic treatment (PDT) elicits diverse cellular responses and can also cause apoptosis. In the present study the cascade of signalling events involved in PDT-induced apoptosis was investigated using Rose Bengal (RB) as the photosensitizer, and human epidermal carcinoma A431 cells as the cell model. We show that a 36-kDa kinase detected by an in-gel kinase assay is markedly activated during PDT-triggered apoptosis. Immunoblot analysis revealed that this 36-kDa kinase represents the C-terminal catalytic fragment of p21-activated kinase (PAK)2. Generation of this active fragment of PAK2 is mediated by the caspase family of proteases, which are activated by PDT. The specific caspase inhibitors (acetyl-Asp-Glu-Val-Asp-aldehyde and acetyl-Tyr-Val-Ala-Asp-chloromethylketone) block the PDT-induced caspase-3 activation and subsequent PAK2 cleavage/activation, indicating a major role for the caspase family proteases in PDT-induced apoptosis. Both PDT-induced caspase-3 activation and PAK2 cleavage/activation can be inhibited by the singlet oxygen scavengers, L-histidine and alpha-tocopherol, but not the hydroxyl radical scavenger, mannitol, demonstrating that singlet oxygen is an immediate early-apoptotic signal generated by PDT. In addition, PDT can induce a two-stage activation of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) in A431 cells; the early-stage JNK activation is singlet oxygen-dependent, whereas the late-stage JNK activation is mediated by the singlet oxygen-triggered caspase activation. Experiments using anti-sense oligonucleotides against JNK1 and PAK2 further show that during PDT-induced apoptosis the early-stage JNK activation is required for caspase activation, and that the late-stage JNK activation is regulated by the caspase-mediated cleavage/activation of PAK2. Collectively, a model for the PDT-triggered apoptotic signalling cascade with RB is proposed, which involves singlet oxygen, JNK, caspase-3 and PAK2, sequentially.

Suppression of proline-directed protein kinase F(A) expression potentiates erythroid differentiation of human myeloid leukemia cells

BACKGROUND

Initial clinic studies revealed that the overexpression of proline-directed protein kinase F(A) (PDPK F(A)) is associated conversely with various stages of tumor tissue differentiation. However, the role of overexpressed PDPK F(A) in tumor cell differentiation remains unknown and needs to be established. In this report, the authors explore the potential role of PDPK F(A) in cellular differentiation by investigating the effects of partial inhibition of this kinase on erythroid differentiation of chronic myeloid leukemia cells (K562).

METHODS

PDPK F(A) antisense expression vector and its specific antibody were developed successfully. Two stable, transfected antisense clones of human myeloid leukemia cells were subcloned that expressed approximately 80% and approximately 50% of the total PDPK F(A) existing in control-transfected clones, as determined by both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, the PDPK F(A) antisense clones expressed no significant suppression of any other related PDPK members' expression, demonstrating the specificity of these two antisense clones.

RESULTS

The antisense clones proportionally induced spontaneous erythroid differentiation up to approximately 30% of the total K562 cells. Moreover, antisense suppression of PDPK F(A) expression appeared to potentiate sodium butyrate/hemin-induced erythroid differentiation of K562 cells to a more complete stage compared with the control.

CONCLUSIONS

The results demonstrate that specific antisense suppression of overexpressed PDPK F(A) in human myeloid leukemia cells is sufficient to potentiate both spontaneous and drug-induced erythroid differentiation, indicating that PDPK F(A) is an important negative regulator in controlling the erythroid differentiation of human myeloid leukemia cells.

Suppression of proline-directed protein kinase F(A) expression inhibits the growth of human chronic myeloid leukaemia cells

Initial studies revealed that proline-directed protein kinase F(A) (PDPK F(A)) was overexpressed in various cancerous tissues relative to normal controls. However, the functional role of overexpressed PDPK F(A) in cancer remains to be established. In this report, we explore the potential role of PDPK F(A) in leukaemia cell growth by investigating the effects of partial inhibition of this kinase on the malignant phenotype of human chronic myeloid leukaemia cells (K562). Cloning of PDPK F(A) cDNA and its recombinant antisense expression vector and PDPK F(A)-specific antibody were successfully developed. Two stable antisense clones of K562 cells were subcloned which expressed 70% and 45% of PDPK F(A) respectively, compared with control-transfected clone in both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, these two antisense clones expressed no significant suppression of any other related PDPK family members, indicating the specificity of these two antisense clones. Moreover, these antisense clones proportionally and potentially exhibited cell growth retardation, poor clonogenic growth in soft agar and loss of serum independence. The results demonstrate that specific antisense suppression of PDPK F(A) is sufficient to interfere with the growth of K562 cells, indicating that PDPK F(A) is essential for human chronic myeloid leukaemia cell growth.

Antisense suppression of proline-directed protein kinase FA enhances chemosensitivity in human prostate cancer cells

Initial clinic studies revealed that proline-directed protein kinase FA (PDPK FA) is overexpressed manyfold in various human cancerous tissues relative to the normal control. However, the role of overexpressed PDPK FA in cancers remains unknown and needs to be established. To determine whether PDPK FA is associated with drug sensitivity, we investigated the effects of partial inhibition of this kinase on the human prostate carcinoma cell line (PC-3). PDPK FA antisense expression vector and its specific antibody were successfully developed. Two stable transfected antisense clones (PA7 and PA3) of human prostate carcinoma cell were subcloned, and they expressed approximately 75% and approximately 35% of the total PDPK FA existing in the control-transfected clone as determined by both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, the PDPK FA antisense clones expressed no significant suppression of any other related proline-directed protein kinase member expression, demonstrating the specificity of these two antisense clones. When compared with parental or control-transfected cells, the low-PDPK FA-expressing antisense clones displayed an enhanced sensitivity to carboplatin, 5-fluorouracil, paclitaxel, and hydroxyurea. Estimation of the IC50 index further revealed that the antisense clones displayed up to > 100-fold drug sensitivity, and there was a correlation between suppressed levels of PDPK FA and drug sensitivity. Taken together, the results demonstrate that specific antisense suppression of overexpressed PDPK FA in human prostate cancer cells is sufficient to enhance various drug sensitivity, indicating that PDPK FA is an important regulator in controlling multiple drug resistance of human prostate cancer cells.

PAK2 is cleaved and activated during hyperosmotic shock-induced apoptosis via a caspase-dependent mechanism: evidence for the involvement of oxidative stress

Hyperosmotic shock elicits a stress response in mammalian cells and can lead to apoptotic cell death. In the present study, we report that hyperosmotic shock can induce activation of a 36 kDa kinase detected by an in-gel kinase assay in several cell types, including mouse Balb/c 3T3 fibroblasts, and human Hep 3B and A431 cells. This 36 kDa kinase can be recognized by an antibody against the C-terminal region of a family of p21Cdc42/Rac-activated kinases (PAKs) on immunoblot. Further studies with this antibody and a PAK2-specific antibody against the N-terminal region of PAK2 demonstrate that hyperosmotic shock can induce cleavage of PAK2 to generate a 36 kDa C-terminal catalytic fragment in cells. The cleavage and activation of PAK2 was found to be closely associated with both DNA fragmentation and activation of an ICE/CED-3 family cysteine protease termed caspase-3 in hyperosmotically shocked cells. Furthermore, pretreating the cells with two caspase inhibitors (Ac-DEVD-cho and Ac-YVAD-cmk) could inhibit both cleavage/activation of PAK2 and DNA fragmentation induced by hyperosmotic shock. Moreover, all these hyperosmotic shock-induced changes (i.e., activation of caspase-3, cleavage/activation of PAK2, and DNA fragmentation) in cells could be blocked by antioxidants such as ascorbic acid (vitamine C), alpha-tocopherol (vitamine E), dithiothreitol, beta-mercaptoethanol, and glutathione. Taken together, our results show that PAK2 is cleaved and activated via a caspase-dependent mechanism during hyperosmotic shock-induced apoptosis and suggest the involvement of antioxidant-preventable oxidative stress in inducing this process.

Proteolytic cleavage and activation of PAK2 during UV irradiation-induced apoptosis in A431 cells

Exposure of mammalian cells to ultraviolet (UV) light elicits a cellular response and can also lead to apoptotic cell death. In this report, we show that a 36-kDa myelin basic protein (MBP) kinase detected by an in-gel kinase assay can be dramatically activated during the early stages of UV irradiation-triggered apoptosis of A431 cells. Immunoblot analysis revealed that this 36-kDa MBP kinase could be recognized by an antibody against the C-terminal regions of a family of p21Cdc42/Rac-activated kinases (PAKs). By using this antibody and a PAK2-specific antibody against the N-terminal region of PAK2 as studying tools, we further demonstrated that UV irradiation caused cleavage of PAK2 to generate a 36-kDa C-terminal catalytic fragment and a 30-kDa N-terminal fragment in A431 cells. The appearance of the 36-kDa C-terminal catalytic fragment of PAK2 matched exactly with the activation of the 36-kDa MBP kinase in A431 cells upon UV irradiation. In addition, UV irradiation also led to activation of CPP32/caspase-3, but not ICH-1L/caspase-2 and ICE/caspase-1, in A431 cells and the kinetics of activation of CPP32/caspase-3 appeared to correlate well with that of DNA fragmentation and of cleavage/activation of PAK2, respectively. Moreover, blockage of activation of CPP32/caspase-3 by pretreating the cells with two specific tetrapeptidic inhibitors for caspases (Ac-DEVD-cho and Ac-YVAD-cmk) could significantly attenuate the extent of cleavage/activation of PAK2 induced by UV irradiation. Collectively, the results demonstrate that cleavage and activation of PAK2 can be induced during the early stages of UV irradiation-triggered apoptosis and indicate the involvement of CPP32/caspase-3 in this process.

Identification of the regulatory autophosphorylation site of autophosphorylation-dependent protein kinase (auto-kinase). Evidence that auto-kinase belongs to a member of the p21-activated kinase family

Autophosphorylation-dependent protein kinase (auto-kinase) was identified from pig brain and liver on the basis of its unique autophosphorylation/activation property [Yang, Fong, Yu and Liu (1987) J. Biol. Chem. 262, 7034-7040; Yang, Chang and Soderling (1987) J. Biol. Chem. 262, 9421-9427]. Its substrate consensus sequence motif was determined as being -R-X-(X)-S*/T*-X3-S/T-. To characterize auto-kinase further, we partly sequenced the kinase purified from pig liver. The N-terminal sequence (VDGGAKTSDKQKKKAXMTDE) and two internal peptide sequences (EKLRTIV and LQNPEK/ILTP/FI) of auto-kinase were obtained. These sequences identify auto-kinase as a C-terminal catalytic fragment of p21-activated protein kinase 2 (PAK2 or gamma-PAK) lacking its N-terminal regulatory region. Auto-kinase can be recognized by an antibody raised against the C-terminal peptide of human PAK2 by immunoblotting. Furthermore the autophosphorylation site sequence of auto-kinase was successfully predicted on the basis of its substrate consensus sequence motif and the known PAK2 sequence, and was further demonstrated to be RST(P)MVGTPYWMAPEVVTR by phosphoamino acid analysis, manual Edman degradation and phosphopeptide mapping via the help of phosphorylation site analysis of a synthetic peptide corresponding to the sequence of PAK2 from residues 396 to 418. During the activation process, auto-kinase autophosphorylates mainly on a single threonine residue Thr402 (according to the sequence numbering of human PAK2). In addition, a phospho-specific antibody against a synthetic phosphopeptide containing this identified sequence was generated and shown to be able to differentially recognize the activated auto-kinase autophosphorylated at Thr402 but not the non-phosphorylated/inactive auto-kinase. Immunoblot analysis with this phospho-specific antibody further revealed that the change in phosphorylation level of Thr402 of auto-kinase was well correlated with the activity change of the kinase during both autophosphorylation/activation and protein phosphatase-mediated dephosphorylation/inactivation processes. Taken together, our results identify Thr402 as the regulatory autophosphorylation site of auto-kinase, which is a C-terminal catalytic fragment of PAK2.

Heat shock stress induces cleavage and activation of PAK2 in apoptotic cells

Heat shock induces a stress response in mammalian cells and can also lead to apoptotic cell death. Here we report that a 36-kDa myelin basic protein (MBP) kinase detected by an in-gel kinase assay can be drastically activated in several cell types by heat shock. Immunoblot analysis revealed that this 36-kDa MBP kinase can be recognized by an antibody against the C-terminal region of a family of p21Cdc42/Rac-activated kinases (PAKs). By using this antibody and a PAK2-specific antibody against the N-terminal region of PAK2 as tools, we further demonstrated that heat shock can induce cleavage of PAK2 to generate a 36-kDa C-terminal catalytic fragment in mouse Balb/c 3T3 and human Hep 3B cells. The kinetic profile of appearance of the 36-kDa C-terminal catalytic fragment of PAK2 matched exactly with the activation of the 36-kDa MBP kinase in these cells induced by heat shock. In addition, the heat shock-induced cleavage and activation of PAK2 was found to be closely associated with both DNA fragmentation and activation of an ICE/CED-3 family cysteine protease termed caspase-3 in heat shock-treated Hep 3B cells. Moreover, blockage of the activation of caspase-3 by pretreating the cells with two specific tetrapeptidic inhibitors of caspases (Ac-DEVD-cho and Ac-YVAD-cmk) could substantially diminish the extent of heat shock-induced cleavage/activation of PAK2. Overall, our results point out that PAK2 is cleaved and activated during the heat shock-induced apoptotic cell death process and suggest that caspase-3 is involved in this process.

Differential tyrosine phosphorylation/activation of oncogenic proline-directed protein kinase F(A)/GSK-3alpha in well and poorly differentiated human prostate carcinoma cells

Computer analysis of protein phosphorylation site sequences revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of proline-directed protein kinase F(A)/glycogen synthase kinase-3alpha (PDPK F(A)/GSK-3alpha) has been optimized to demonstrate significantly increased (p < 0.01) activity in poorly differentiated human prostate carcinoma PC-3 cells (55.5+/-3.8 units/mg) when compared to well-differentiated LNCaP cells (28.1+/-2.3 units/mg). Immunoblotting analysis revealed that increased activity of this PDPK in PC-3 cells is due not to overexpression of the protein, but to enhanced tyrosine phosphorylation of the kinase. When treated with genistein (a protein tyrosine kinase PTK inhibitor), the enhanced tyrosine phosphorylation/activation of the kinase in PC-3 cells can be blocked. Conversely, when treated with vanadate (a protein tyrosine phosphatase PTP inhibitor), the phosphotyrosine content of PDPK F(A)/GSK-3alpha in LNCaP cells can be promoted to the level of PC-3 cells. In sharp contrast, the PTK inhibitor has little effect on the tyrosine phosphorylation level of the kinase in LNCaP cells, whereas the PTP inhibitor has little effect on the tyrosine phosphorylation level of the kinase in PC-3 cells. Taken together, the results provide initial evidence that the tyrosine phosphorylation/activation levels of this oncogenic PDPK can be differentially regulated in well- and poorly differentiated prostate carcinoma cells.

Acute inductive effects on oncogenic proline-directed protein kinase FA/GSK-3 alpha in NIH 3T3 cells by ethanol and cadmium

Exposure of NIH 3T3 cells to 375 mM ethanol at 37 degrees C for 20 min could induce a rapid increase in the protein level and cellular activity of oncogenic proline-directed protein kinase FA/glycogen synthase kinase-3 alpha (PDPK FA/GSK-3 alpha), up to approximately 300% of the control level, in a time- and concentration-dependent manner. The maximal inductive effect on PDPK FA/GSK-3 alpha also occurred within 40 min when cells were treated with only 100 mM ethanol. Similarly, exposure of NIH 3T3 cells to 100 microM cadmium for 2 h could induce a rapid increase in the protein level and cellular activity of PDPK FA/GSK-3 alpha, up to approximately 250% of the control level, in a time- and concentration-dependent manner. The maximal inductive effect on this kinase reached within 3 h when cells were treated with only 50 microM cadmium. The results demonstrate that PDPK FA/GSK-3 alpha may not represent a constitutively active/mitogen-inactivated protein kinase as previously conceived. Taken together with the previous report that PDPK FA/GSK-3 alpha is a heat-inducible protein kinase, the results further demonstrate that PDPK FA/GSK-3 alpha may represent a typical cellular stresses-inducible protein kinase subject to early induction by heat, ethanol and cadmium.

Bioflavonoids commonly and potently induce tyrosine dephosphorylation/inactivation of oncogenic proline-directed protein kinase FA in human prostate carcinoma cells

In this study, we investigate the effect of bioflavonoids on the activity and phosphotyrosine content of oncogenic proline-directed protein kinase FA (PDPK FA) in human prostate carcinoma cells. Chronic treatment of human prostate carcinoma cells with low concentrations of quercetin, apigenin, and kaempferol commonly and potently induced tyrosine dephosphorylation and concurrent inactivated oncogenic PDPK FA in a concentration-dependent manner. This is demonstrated by a specific assay of this kinase's activity in the immunoprecipitates from the cell extracts followed by immunoblotting and phosphotyrosine analysis. The results indicate that bioflavonoids may function as common tyrosine kinase inhibitors to inhibit PDPK FA-specific tyrosine kinase and thereby to induce tyrosine dephosphorylation/inactivation of this oncogenic kinase in human carcinoma cells. Under this condition, quercetin, apigenin, and kaempferol can also inhibit cell growth in a similar concentration-dependent manner. The results further indicate that inhibition of tyrosine phosphorylation/activation of this oncogenic PDPK represents a new mode of action mechanism for bioflavonoids during the antiproliferation process in human carcinoma cells.

The naturally occurring PKC inhibitor sphingosine and tumor promoter phorbol ester potentially induce tyrosine phosphorylation/activation of oncogenic proline-directed protein kinase FA/GSK-3alpha in a common signalling pathway

When serum-starved A431 cells were treated with 200 nM phorbol ester TPA for 15 min, the cellular activity of protein kinase FA/glycogen synthase kinase-3alpha (kinase FA/GSK-3alpha) could be decreased to approximately 25% of control. Conversely, when treated with 1 microM TPA for 24 hr, the activity could be reversibly increased to approximately 200% of Control. The naturally occurring protein kinase C (PKC) inhibitor sphingosine at a concentration of 27 microM could also induce activation of kinase FA/GSK-3alpha to approximately 200% of control within 60 min. Further, when cells were chronically treated with 1 microM TPA for 24 hr and then with 27 microM sphingosine for 60 min, the activity of kinase FA/GSK-3alpha could only be increased to approximately 200% of control. Furthermore, when cells were pretreated with sphingosine and then acutely treated with TPA, the acute TPA effect on kinase FA/GSK-3alpha activity could be abolished by genistein or tyrosine phosphorylation, which could be blocked by genistein or tyrosine phosphatase, but could be reversed by orthovanadate. Taken together, the results demonstrate that TPA/sphingosine induce tyrosine phosphorylation and concurrent activation of kinase FA/GSK-3alpha in a common signalling pathway. Since TPA and sphingosine are potent PKC modulators, the results further suggest a potential role of PKC in modulating tyrosine phosphorylation/activation of kinase FA/GSK-3alpha. Kinetic studies on seven subtypes of PKC further demonstrate a specific involvement of PKCE in this tyrosine phosphorylation/activation process. This provides a new mode of signal transduction between these two important serine/threonine kinases in cells.

Selective interaction of protein kinase FA/glycogen synthase kinase-3alpha with membrane phospholipids

Previously we reported that the activity of protein kinase FA/glycogen synthase kinase-3alpha (kinase FA/GSK-3alpha) can be detected in several brain membrane fractions. In this report, we examined whether kinase FA/GSK-3alpha can directly interact with membrane phospholipids by using anti-kinase FA/GSK-3alpha antibody as a more specific studying tool. It was found that kinase FA/GSK-3alpha can associate with NaOH-extracted brain membranes and selectively interact with several kinds of reconstituted phospholipid vesicles including phosphatidic acid (PA), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), and phosphatidyl serine (PS) vesicles. Increasing ionic strength in the reaction could disrupt the interaction between kinase FA/GSK-3alpha and PA, PI, or PE vesicles but had no effect on the interaction between kinase FA/GSK-3alpha and PS vesicles, indicating that both ionic and non-ionic interactions are involved in this process, respectively. Moreover, both kinase activity and protease sensitivity of kinase FA/GSK-3alpha can be affected profoundly by these phospholipid vesicles and different forms of the kinase can be produced when it binds to distinct types of phospholipid vesicles. Taken together, the results demonstrate a direct interaction of kinase FA/GSK-3alpha with membrane phospholipids and suggest that membrane phospholipids may be directly involved in regulating kinase FA/GSK-3alpha activity.

Heat stress induces tyrosine phosphorylation/activation of kinase FA/GSK-3 alpha (a human carcinoma dedifferentiation modulator) in A431 cells

Exposure of A431 cells to a rapid temperature increase from 37 degrees to 46 degrees C could induce an increased expression (approximately 200% of control) and tyrosine phosphorylation/activation (approximately 300% of control) of protein kinase FA/ glycogen synthase kinase-3 alpha (kinase FA/GSK-3 alpha) in a time-dependent manner, as demonstrated by an anti-kinase FA/GSK-3 alpha immunoprecipitate kinase assay and by immunoblotting analysis with anti-kinase FA/GSK-3 alpha and anti-phosphotyrosine antibodies. The heat induction on the increased expression of kinase FA/GSK-3 alpha could be blocked by actinomycin D but not by genistein. In contrast, the heat induction on tyrosine phosphorylation/activation of kinase FA/GSK-3 alpha could be blocked by genistein or protein tyrosine phosphatase, indicating that heat stress induces a dual control mechanism, namely, protein expression and subsequent tyrosine phosphorylation to cause cellular activation of kinase FA/GSK-3 alpha. Taken together, the results provide initial evidence that kinase FA/GSK-3 alpha represents a newly described heat stress-inducible protein subjected to tyrosine phosphorylation/activation, representing a new mode of signal transduction for the regulation of this human carcinoma dedifferentiation modulator and a new mode of heat induction on cascade activation of a protein kinase.

Reversible tyrosine phosphorylation/dephosphorylation of proline-directed protein kinase FA/glycogen synthase kinase-3alpha in A431 cells

Modulation of protein kinase FA/glycogen synthase kinase-3alpha (kinase FA/GSK-3alpha) by reversible tyrosine phosphorylation/dephosphorylation was investigated. In addition to genistein, other protein tyrosine kinase (PTK) inhibitors, such as tyrphostin A47 and B42, also could induce tyrosine dephosphorylation and inactivation of kinase FA/GSK-3alpha in A431 cells, and this process was found to be reversible. Pretreatment of the cells with 100 microM orthovanadate, a protein tyrosine phosphatase (PTP) inhibitor, could diminish significantly the effects of PTK inhibitors on both enzyme activity and phosphotyrosine content of the kinase, suggesting that the PTK inhibitors induced tyrosine dephosphorylation/inactivation of this kinase is mediated by orthovanadate-sensitive PTP(s) in A431 cells. Moreover, the phosphotyrosine moiety of kinase FA/GSK-3alpha was found to be highly turned over in resting cells. Interestingly, we found that the less active, tyrosine-dephosphorylated form of kinase FA/GSK-3alpha immunoprecipitated from genistein-treated cells was able to reactivate partially with concomitant rephosphorylation of tyrosine residue in vitro. Taken together, these findings demonstrate that tyrosine phosphorylation and concomitant activation of kinase FA/GSK-3alpha can be carried out both in vitro and in vivo and an in vivo phosphatase activity may function in antagonism to PTK activation of kinase FA/GSK-3alpha.

Mono(ADP-ribosyl)transferase genes and diabetes in NOD mice. Is there a relationship?

The answer to the question posed by the title (is there a relationship between aberrant Art gene expression and IDDM pathogenesis in NOD mice?) remains elusive. Conclusions are currently based almost entirely upon analysis of mRNA transcript levels rather than on T-cell-specific mono-ADP ribosylation activities. Our unpublished data, as well as data published in abstract form by Dr. L. Chatenoud and colleagues (48) indicate that gene transcription is not impaired in splenic leukocytes of older NOD mice, including those with spontaneous IDDM development. Based upon the limited data showing that there may be reduced expression of Art gene products in the earliest T cell immigrants from the NOD thymus, one would have to surmise that If there is a regulatory defect, it may be in allowing single positive thymic T cells to emigrate before they are fully mature. Therefore, development of anti-Art monoclonal antibody together with further studies regarding functions of mono(ADP-ribosyl)transferase in immunoregulation of different subpopulation of T-cells, may finally resolve the role that altered mono(ADP-ribosyl)transferase activities play in the pathogenesis of IDDM in NOD mice.

Activation of the ATP.Mg-dependent type 1 protein phosphatase by the Fe2+/ascorbate system

The ATP.Mg-dependent type 1 protein phosphatase is inactive as isolated but can be activated in several different ways. In this report, we show that the phosphatase can also be activated by the Fe2+/ascorbate system. Activation of the phosphatase requires both Fe2+ ion and ascorbate and the level of activation is dependent on the concentrations of Fe2+ ion and ascorbate. In the presence of 20 mM ascorbate, the Fe2+ ion concentrations required for half-maximal and maximal activation are about 0.3 and 3 mM, respectively. Several common divalent metal ions, including CO2+, Ni2+, Cu2+, Mg2+, and Ca2+ ions, cannot cooperate with ascorbate to activate the phosphatase, and SH-containing reducing agents such as 2-mercaptoethanol and dithiothreitol cannot cooperate with Fe2+ ion to activate the phosphatase, indicating that activation of the phosphatase by the Fe2+/ascorbate system is a specific process. Moreover, H2O2, a strong oxidizer, could significantly diminish the phosphatase activation by the Fe2+/ascorbate system, suggesting that reduction mechanism other than SH-SS interchange is a prerequisite for the Fe2+/ascorbate-mediated phosphatase activation. Taken together, the present study provides initial evidence for a new mode of type 1 protein phosphatase activation mechanism.

Overexpression of protein kinase FA/GSK-3 alpha (a proline-directed protein kinase) correlates with human hepatoma dedifferentiation/progression

Computer analysis of protein phosphorylation sites sequence revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of protein kinase FA/glycogen synthase kinase-3 alpha (kinase F(A)/GSK-3 alpha) (a member of PDPK family) has been optimized for human hepatoma and used to demonstrate for the first time significantly increased (P < 0.01) activity in poorly differentiated SK-Hep-1 hepatoma (24.2 +/- 2.8 units/mg) and moderately differentiated Mahlavu hepatoma (14.5 +/- 2.2 units/mg) when compared to well differentiated Hep 3B hepatoma (8.0 +/- 2.4 units/mg). Immunoblotting analysis revealed that increased activity of kinase FA/GSK-3 alpha is due to overexpression of the protein. Elevated kinase FA/GSK-3 alpha expression in human hepatoma biopsies relative to normal liver tissue was found to be even more profound. This kinase appeared to be fivefold overexpressed in well differentiated hepatoma and 13-fold overexpressed in poorly differentiated hepatoma when compared to normal liver tissue. Taken together, the results provide initial evidence that overexpression of kinase FA/GSK-3 alpha is involved in human hepatoma dedifferentiation/progression. Since kinase FA/GSK-3 alpha is a PDPK, the results further support a potential role of this kinase in human liver tumorigenesis, especially in its dedifferentiation/progression.

Okadaic acid, sphingosine, and phorbol ester reversibly modulate heat induction on protein kinase FA/GSK-3 alpha in A431 cells

Exposure of A431 cells to a rapid and sudden increase from 37 degrees C to 46 degrees C for 30 min could induce an increase in protein level and cellular activity of protein (kinase FA/GSK-3 alpha) up to approximately 200% of control level. However, when cells were first treated with 500 nM tumor promoter phorbol ester TPA at 37 degrees C for 30 min to activate cellular protein kinase C (PKC) or with 400 nM okadaic acid at 37 degrees C for 30 min to inhibit cellular protein phosphatases followed by heat shock at 46 degrees C for another 30 min, the heat induction on kinase FA/GSK-3 alpha was found to be completed blocked. In sharp contrast, when cells were first treated with 1 microM TPA at 37 degrees C for 24 h or with 5 microM sphingosine at 37 degrees C for 30 min to down-regulate cellular PKC, the heat induction on kinase FA/GSK-3 alpha was found to be reversely promoted up to approximately 250% of control level, demonstrating that kinase FA/GSK-3 alpha may not represent a constitutively active/mitogen-inactivated protein kinase as previously conceived. Taken together, the results provide initial evidence that TPA/sphingosine and okadaic acid could reversibly modulate the heat induction on kinase FA/GSK-3 alpha in A431 cells, suggesting that phosphorylation/dephosphorylation mechanisms are involved in the regulation of the heat-shock induction of kinase FA/GSK-3 alpha, representing a new mode of signal transduction for the regulation of this multisubstrate protein kinase and a new mode of signaling pathway modulating the heat-induction process.