Knockdown of SETD2 promotes erastin-induced ferroptosis in ccRCC

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer and is associated with poor prognosis. The histone H3 lysine 36 methyltransferase SET-domain-containing 2 (SETD2) has been reported to be expressed at low levels and frequently mutated in ccRCC. Ferroptosis, a form of death distinct from apoptosis and necrosis, has been reported in recent years in renal cancer. However, the relationship between SETD2 and ferroptosis in renal cancer is not clear. Here, we demonstrated that SETD2 was expressed at low levels in ccRCC and was associated with poor prognosis. Moreover, we found that knockdown of SETD2 increased lipid peroxidation and Fe2+ levels in tumor cells, thereby increasing the sensitivity of erastin, a ferroptosis inducer. Mechanistically, histone H3 lysine 36 trimethylation (H3K36me3) which was catalyzed by SETD2, interacted with the promoter of ferrochelatase (FECH) to regulate its transcription and ferroptosis-related signaling pathways. In conclusion, the presesnt study revealed that knockdown of the epigenetic molecule, SETD2, significantly increases the sensitivity of ferroptosis inducers which promotes tumor cell death, thereby indicating that SETD2 may be a potential therapeutic target for ccRCC.

RBM4 inhibits the growth of clear cell renal cell carcinoma by enhancing the stability of p53 mRNA

RBM4 has been reported as a tumor suppressor gene in cancers, including lung cancer, colon cancer and gastric cancer. However, the role of RBM4 in clear cell renal cell carcinoma (ccRCC) remains unclear. Therefore, the present study investigated the expression and biological function of RBM4 in ccRCC. Analysis of the differential expression of RBM4 and its relationship with clinicopathological features using ccRCC samples data from TCGA database deminstrated that RBM4 expression in tumor samples of ccRCC was lower than that in normal samples, and RBM4 expression was closely related to the survival time of patients. RBM4 overexpression (RBM4-oe) cell lines were constructed to investigate the effect of RBM4 on biological function using CCK-8, EdU, flow cytometry and wound-healing assays. In addition, the regulatory effect of RBM4 on signaling pathways was investigated by GSEA and WB assays. RBM4-oe significantly reduced the proliferation of ccRCC cells by controlling the p53 signaling pathway, inhibited cell cycle progression and promoted apoptosis. In addition, RBM4-oe suppressed the migration and invasion of cells by EMT. Mechanistically, RBM4-oe facilitated the activity of the p53 signaling pathway by enhancing the stability of p53 mRNA. Finally, RBM4-oe markedly inhibited the growth of tumors formed with 786-O cells in vivo. In summary, there findings suggeated that RBM4 inhibits the progression of ccRCC by promoting p53 signaling pathway activity by enhancing the stability of p53 mRNA, suggesting that RBM4 may be a potential target for the treatment of patients.

Integration analysis identifies MYBL1 as a novel immunotherapy biomarker affecting the immune microenvironment in clear cell renal cell carcinoma: Evidence based on machine learning and experiments

Background

Previous studies have identified MYBL1 as a cancer-promoting molecule in numerous types of cancer. Nevertheless, the role of MYBL in renal cancer remains unclear.

Methods

Genomic and clinical data of clear cell renal cell carcinoma (ccRCC) was get from the Cancer Genome Atlas (TCGA) database. CCK8, colony formation, and 5-ethynyl-2'-deoxyuridine assay were utilized to evaluate the performance of cell proliferation. Cell apoptosis was detected using the flow cytometric analysis. The protein level of MYBL1 in different tissues was evaluated using immunohistochemistry. A machine learning algorithm was utilized to identify the prognosis signature based on MYBL1-derived molecules.

Results

Here, we comprehensively investigated the role of MYBL1 in ccRCC. Here, we noticed a higher level of MYBL1 in ccRCC patients in both RNA and protein levels. Further analysis showed that MYBL1 was correlated with progressive clinical characteristics and worse prognosis performance. Biological enrichment analysis showed that MYBL1 can activate multiple oncogenic pathways in ccRCC. Moreover, we found that MYBL1 can remodel the immune microenvironment of ccRCC and affect the immunotherapy response. In vitro and in vivo assays indicated that MYBL1 was upregulated in ccRCC cells and can promote cellular malignant behaviors of ccRCC. Ultimately, an machine learning algorithm - LASSO logistics regression was utilized to identify a prognosis signature based on the MYBL1-derived molecules, which showed satisfactory prediction ability on patient prognosis in both training and validation cohorts.

Conclusions

Our result indicated that MYBL1 is a novel biomarker of ccRCC, which can remodel the tumor microenvironment, affect immunotherapy response and guide precision medicine in ccRCC.

FBXL6 depletion restrains clear cell renal cell carcinoma progression

BACKGROUND

F-box proteins play important roles in cell cycle and tumorigenesis. However, its prognostic value and molecular function in clear cell renal cell carcinoma (ccRCC) remain unclear. In this study, we established a survival model to evaluate the prognosis of patients with ccRCC using the F-box gene signature and investigated the function of FBXL6 in ccRCC.

METHODS

Comprehensive bioinformatics analyses were used to identify differentially expressed F-box and hub genes associated with ccRCC carcinogenesis. Based on the F-box gene signature, we constructed a risk model and nomogram to predict the overall survival (OS) of patients with ccRCC and assist clinicians in decision-making. Finally, we verified the function and underlying molecular mechanisms of FBXL6 in ccRCC using CCK-8 and EdU assays, flow cytometry, and subcutaneous xenografts.

RESULTS

A risk model based on FBXO39, FBXL6, FBXO1, and FBXL16 was developed. In addition, we drew a nomogram based on the risk score and clinical features to assess the prognosis of patients with ccRCC. Subsequently, we identified FBXL6 as an independent prognostic marker that was highly expressed in ccRCC cell lines. In vivo and in vitro assays revealed that the depletion of FBXL6 inhibited cell proliferation and induced apoptosis. We also demonstrated that SP1 regulated the expression of FBXL6.

CONCLUSIONS

FBXL6 was first identified as a diagnostic and prognostic marker in patients with ccRCC. Loss of FBXL6 attenuates proliferation and induces apoptosis in ccRCC cells. SP1 was also found to regulate the expression of FBXL6.

Development and validation of a novel nomogram to predict chronic total occlusion before coronary angiography

OBJECTIVE

Some previous studies have analyzed potential predictors related to the high incidence rate of coronary artery disease (CAD) and established a relevant nomogram for CAD in patients before coronary angiography (CAG). Nevertheless, there are still few models to predict chronic total occlusion (CTO). In this study, we aimed to construct a risk model and nomogram that could effectively predict the probability of CTO before CAG.

PATIENTS AND METHODS

In total, the derivation set (n=1,105) and the validation set (n=368), which included patients with CAG diagnosis of CTO, were collected. A statistical difference test was performed for clinical, demography, echocardiography, medication history, laboratory indexes, and angiography. Univariate and multivariate logistic regression analysis were performed to determine the independent risk factors that affect the diagnosis of CTO. A nomogram was established and validated based on the independent predictors. The area under the curve (AUC), the calibration curve, and the decision curve analysis (DCA) were used to evaluate the nomogram.

RESULTS

The incidence of CTO within CAD was 21.5%. Univariate and multivariate logistic regression analysis revealed that risk factors for gender (male), neutrophil percentage (NE%), hematocrit (HCT), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), ejection fraction (EF), troponin I (TnI), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independent predictors of CTO. A nomogram was constructed incorporating these independent predictors with good discrimination (0.746 in the C-index) and external validation (0.741 in the C-index). The calibration curves and the DCA showed the reliability and accuracy of this clinical prediction model.

CONCLUSIONS

The nomogram, composed of gender, NE%, HCT, TC, HDL, EF, TnI, and NT-proBNP, can be used for the prediction of CTO in CAD patients, which opens a great possibility of enriching the means to predict the prognosis of these patients in clinical practice. More studies are needed to validate the effectiveness of this nomogram in other populations.

A pyroptosis-associated signature plays a role in prognosis prediction in clear cell renal cell carcinoma

Background

Approximately 90% of renal malignancies are RCCs (renal cell carcinomas), and the primary subtype in histology is ccRCC (clear cell RCC). In recent years, pyroptosis has been considered a kind of inflammation-related programmed cell death that participates in the invasion, metastasis, and proliferation of tumour cells, thereby influencing tumour prognosis. Nonetheless, the expression level of pyroptosis-associated genes in RCCs and their relationship with prognosis remain obscure.

Results

In our research, 44 regulators of pyroptosis that were differentially expressed between normal kidney and ccRCC tissues were identified. ccRCC cases were categorized into 2 subgroups according to prognostic-related DEGs (differentially expressed genes), and there was a significant difference in OS (overall survival) between them. The prognostic value of pyroptosis-associated genes was assessed as a signature based on a cohort from TCGA (The Cancer Genome Atlas). Following Cox regression with DEGs and LASSO (least absolute shrinkage and selection operator), a 6-gene signature was established, and all ccRCC cases in the cohort from TCGA were categorized into an LR (low-risk) or HR (high-risk) group (P < 0.001). In combination with clinical features, risk scores were considered a predictive factor of OS in ccRCC. KEGG (Kyoto Encyclopedia of Genes and Genomes) and GO (Gene Ontology) analyses suggest increased immunity and enrichment of genes related to immunity in the HR group.

Conclusions

Our findings indicate that genes related to pyroptosis have an important role in tumour immunity and may be used to predict the prognosis of ccRCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01339-0.

[Comparison of different evaluation systems for assessing disease severity and treatment efficacy in patients with chronic obstructive pulmonary disease]

OBJECTIVE

To compare the practicability and clinical value of different evaluation systems for assessing disease severity and treatment efficacy in patients with chronic obstructive pulmonary disease (COPD).

METHODS

We retrospectively analyzed the clinical data of 28 patients with acute exacerbation of COPD admitted to our hospital between November, 2020 and January, 2021. All the patients were assessed with percentage of predicted forced expiratory volume in 1 second (FEV1% pred), COPD assessment test (CAT), modified British Medical Research Council (mMRC), baseline dyspnea index (BDI), clinical COPD questionnaire (CCQ), St. George's respiratory questionnaire (SGRQ), BODE index, Hamilton Depression Rating Scale (HDRS) at admission and with CAT, mMRC, transition dyspnea index (TDI), CCQ, SGRQ, and HDRS at 1 month after discharge. The correlations among FEV1% pred, CAT, mMRC, BDI, CCQ, SGRQ, BODE and HDRS at admission were analyzed. We also compared the TDI and scores of CAT, mMRC, CCQ, SGRQ, and HDRS at 1 month after discharge among the patients using single (n=8), dual (n=10) or triple inhaled medications (n=10) after discharge.

RESULTS

Among these patients, FEV1% pred was moderately correlated with SGRQ and BDI (r=-0.66, r=0.61; P < 0.01), and CCQ activity score was closely correlated with mMRC, SGRQ activity score and BDI (r=0.82, r=0.92, r=-0.89; P < 0.01). SGRQ activity score was closely correlated with mMRC and BDI (r=0.84, r=-0.91; P < 0.01), and SGRQ symptom score was closely correlated with BODE (r=0.80, P < 0.01). SGRQ impact score was moderately correlated with HDRS (r=0.57, P < 0.01). In all the 28 patients, all the evaluation scores except for CCQ mental score and HDRS improved significantly after treatment (P < 0.05). At 1 month after discharge, CCQ total score decreased significantly in single therapy group (P < 0.05); CAT, mMRC, CCQ and SGRQ improved obviously in dual therapy group (P < 0.05); CCQ and SGRQ scores decreased significantly in triple therapy group (P < 0.05); the TDI did not differ significantly among the 3 groups (P>0.05).

CONCLUSION

For patients with COPD, BDI and TDI are recommended over mMRC for assessing dyspnea. CAT, CCQ and SGRQ allow sensitive assessment of the treatment efficacy to serve as routine evaluation tests, and among them SGRQ is the most comprehensive and is thus recommended when sufficient time is allowed. BODE is relatively complex but highly valuable for predicting the patients'survival outcomes. HDRS is recommended for routine screening of depression in patients with COPD.

Inhibition of MicroRNA-381 Promotes Tumor Cell Growth and Chemoresistance in Clear-Cell Renal Cell Carcinoma

Background

MicroRNA-381 (miR-381) is proven to be involved in many human tumors. Bioinformatics prediction suggests that miR-381 is decreased in renal cell carcinoma. However, its biological functions in clear-cell renal cell carcinoma (ccRCC) remain largely unknown. The present research aimed to evaluate miR-381 expression in renal cancer tissues and its effects on cell proliferation, growth, migration, and chemoresistance.

Material/Methods

Sixty pairs of ccRCC and the adjacent non-tumor specimens were collected during routine therapeutic surgery. Quantitative real-time PCR (qRT-PCR) assay was employed to examine miR-381 expression in the ccRCC tissues and the associated adjacent tissues (the normal tissues adjacent to tumor tissues). Cell transfection assay and Thiazolyl Blue Tetrazolium Bromide (MTT) assay were utilized to observe effects of miR-381 on the cell proliferation, growth, invasion, and chemoresistance in the Caki-1 cell line and 786-O cell line. Flow cytometry was used to assess cell apoptosis. Caki-1 cell and 786-O cell Xenograft BALB/c mouse models were established.

Results

miR-381 expression was downregulated in ccRCC tissues in vivo and in cell lines in vitro. Downregulation of miR-381 promoted growth of cells and restrained the ccRCC cell apoptosis. Increased miR-381 combined with Ci and Pa suppressed the proliferation and enhanced the anti-tumor effects of Ci and Pa at tolerated concentrations in vitro. miR-381 inhibition promoted chemoresistance in vitro.

Conclusions

miR-381 levels were significantly downregulated in renal cancer tissues and miR-381 inhibition promoted tumor cell growth, migration, and chemoresistance.

α-1,2-Mannosidase MAN1C1 Inhibits Proliferation and Invasion of Clear Cell Renal Cell Carcinoma

Background: This study investigated the biological function of the gene MAN1C1 α-mannosidase in renal cell carcinoma. It has been reported that MAN1C1 is probably a potential tumor suppressor gene in Wilms. However, the role of MAN1C1 in human clear cell renal cell carcinoma (ccRCC) has not been reported.

Methods: In this study, MAN1C1 gene over-expression was used to transfect human renal cancer cell lines 786-O and OS-RC-2 to study apoptosis and the underlying mechanisms which influence epithelial-mesenchymal transition.

Results: MAN1C1 was down-regulated in ccRCC and related to the clinicopathological factors and prognosis of ccRCC. We revealed that over-expression MAN1C1 showed anti-tumor effect by inducing apoptosis, as determined by Cell Counting Kit-8 (CCK-8) assay, cell cycle analysis, and western blot analysis. What's more, MAN1C1 over-expression remarkably increased the ratio of Bax/Bcl-2 and inhibited epithelial-mesenchymal transition by increasing the expression of E-CA. In addition, the ratio of Bax/Bcl-2 and E-CA were also increased in MAN1C1 gene over-expression renal cancer cells compared with the control cells.

Conclusion: We find that re-expression of silenced MAN1C1 in ccRCC cell lines inhibited cell viability, colony formation, induced apoptosis, suppressed cell invasion and migration. In conclusion, MAN1C1 is a novel functional tumor suppressor in renal carcinogenesis. This is the first time that the function of MAN1C1 gene has been verified in the renal tumor tissue so far.

The effect of Hsa_circ_0001451 in clear cell renal cell carcinoma cells and its relationship with clinicopathological features

Purpose: Circular RNAs (circRNAs), are a large class of RNAs that from a covalently closed continuous loop and have recently showed huge capabilities as gene regulators in mammals. Although Hsa_circ_0001451 has been investigated in colorectal cancer, it remains unclear about the relationship between Hsa_circ_0001451 and clear cell renal cell carcinoma (ccRCC). Our research aims to reveal the function of Hsa_circ_0001451 in the proliferation and development in ccRCC cells. Methods: The expression of Hsa_circ_0001451 in 52 pairs of ccRCC tissues and paraneoplastic tissues was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between Hsa_circ_0001451 and the clinicopathological features was evaluated using the chi-sequare test. Receiver operating characteristic (ROC) curve was built by SPSS to evaluate the diagnostic values. The effects of Hsa_circ_0001451 on ccRCC cells were determined via a MTT assay, clone formation assay, flow cytometry and Western blot analysis. Results: The expression of Hsa_circ_0001451 was significantly correlated with differentiation (P<0.05). The area under ROC curve of Hsa_circ_0001451 was 0.704 (P<0.05). Knockdown of Hsa_circ_0001451 significantly promoted tumor growth in vitro. Bioinformatics results also displayed that Hsa_circ_0001451 might be involved in the regulation of tumor progression. Conclusion: Taken together, our finding showed that Hsa_circ_0001451 might become a novel potential biomarker in the diagnosis of ccRCC and a potential novel target for the treatment of ccRCC.

Preclinical antitumor and antiangiogenic activity of a metronomic schedule of cisplatin against human transitional cell carcinoma (TCC)

e16018

Background: Conventional cisplatin every 3 weeks is frequently precluded in patients with TCC due to renal dysfunction. A metronomic schedule of other chemotherapeutic agents demonstrates anti-angiogenic and anti-tumor activity coupled with better tolerability. A rationale can be made to preclinically evaluate the activity of a metronomic (weekly or 3 days a week) schedule of cisplatin in a preclinical system of TCC. Methods: The activity of cisplatin was assessed in vitro against HUVECs (human umbilical vein endothelial cells). MTT, flow cytometry with Annexin-FITC and scratch assays were employed to assess proliferation, apoptosis and migration, respectively. The activity of cisplatin was evaluated in vivo in murine xenograft models of TCC. The subcutaneous xenografts included 5 × 106 RT4 or 5637 human TCC cells injected into 6- to 8-week-old female athymic BALB/c nu/nu mice. Cisplatin was administered 4 mg/kg IP (intraperitoneal) weekly for up to 6 weeks and compared with untreated mice. Then, 3 groups of tumor-bearing mice received either no therapy, cisplatin 6 mg/kg weekly or cisplatin 2 mg/kg for 3 days a week for up to 6 weeks. Tumor size is measured twice a week. Nephrotoxicity is assessed by serum creatinine and kidney histopathological examination. IHC (immunohistochemistry) of xenografts is performed to measure proliferation (ki-67), apoptosis (cleaved caspase-3) and angiogenesis (CD31). Results: Cisplatin demonstrated significant anti-proliferative, anti-migration and pro-apoptotic activity against HUVECs in vitro. Cisplatin 4 mg/kg weekly inhibited tumor growth, induced higher apoptosis and down-regulated angiogenesis and proliferation in vivo compared to controls. Results from the experiment comparing cisplatin 6 mg/kg weekly with 2 mg/kg 3 days a week (i.e. more metronomic, with potentially more anti-angiogenic and anti-tumor activity and less nephrotoxic) will be presented. Conclusions: A metronomic schedule of cisplatin inhibits tumor growth and demonstrates anti-angiogenic activity in a preclinical model of human TCC. The clinical evaluation of a metronomic schedule of cisplatin may be warranted.

No significant financial relationships to disclose.

Sunitinib malate is active and synergistic with cisplatin against human urothelial carcinoma in a preclinical model

15632

Background: Sunitinib malate is an oral, multitargeted tyrosine kinase inhibitor of VEGFRs, PDGFRs, KIT, RET, and FLT3, approved multinationally for the treatment of advanced RCC and imatinib-resistant or -intolerant GIST. Angiogenesis and plasma VEGF correlate with poor outcomes in human urothelial carcinoma. We designed a preclinical study to examine the efficacy of sunitinib malate alone and in combination with cisplatin against human urothelial carcinoma in vitro and in a murine xenograft model. Methods: The IC50 for sunitinib malate and cisplatin was determined separately against two human urothelial carcinoma cell lines (TCC-SUP and 5637). Sunitinib malate and cisplatin were also applied concurrently to determine activity of the combination. Immunohistochemical staining was performed to detect expression of VEGFR2 on the cell lines, and to measure modulation of this pathway by sunitinib by measuring phosphorylated (p)VEGFR2. Anti-tumor activity of sunitinib malate alone and in combination with cisplatin was determined in a murine xenograft model bearing 5,637 cells. Results: Both human urothelial carcinoma cell lines were found to express VEGFR2. Sunitinib malate displayed significant activity against both urothelial carcinoma cell lines in vitro at low nanomolar concentrations. Furthermore, sunitinib malate in combination with cisplatin was synergistic in vitro. We observed primarily cytostatic activity for sunitinib malate at both 20 mg/kg and 40 mg/kg orally once daily against a murine xenograft model bearing subcutaneous 5,637 cell tumors during 4 weeks of treatment. Anti-tumor activity of sunitinib malate in combination with cisplatin and correlative studies are being evaluated in the murine xenograft model. Conclusion: Sunitinib malate has anti-tumor activity against human urothelial carcinoma as a single agent and is synergistic in combination with cisplatin in vitro. Sunitinib also has significant efficacy in a murine xenograft model of human urothelial carcinoma. These results warrant further exploration of sunitinib malate as a single agent and in combination with cisplatin chemotherapy in human urothelial carcinoma.

No significant financial relationships to disclose.

Enhanced radiation-mediated cell killing of human cervical cancer cells by small interference RNA silencing of ataxia telangiectasia-mutated protein

The ataxia telangiectasia-mutated (ATM) protein, which is mutated in the inherited disease ataxia telangiectasia (AT), is a key activator of cell cycle checkpoint, initiating cell response to DNA damage and ensuring genomic stability. AT cells exhibit defects in all cellular responses to ionizing radiation and radiomimetic chemicals. Inactivation of ATM may therefore make cells fail to execute many responses to DNA damage and improve the cells' sensitivity to radiation. Recent developments in the use of small interference RNA molecules (siRNAs) to inhibit specific protein expression have highlighted the potential use of siRNA as a therapeutic agent. In this study, we have designed and exogenously delivered plasmids encoding siRNAs targeting ATM to human cervical carcinoma SiHa cells and generated a stable cell line, SiHa(ATM). SiHa(ATM) cells displayed minimal levels of ATM protein and showed a marked increase in sensitivity to radiation. Together, these data provide strong evidence for the potential use of siRNA as a novel radiation/chemotherapy-sensitizing agent.

[Changes in calcium and magnesium levels of lymphocytes in patients with diabetes and hypertension]

To investigate the cellular basis linking non-insulin-dependent diabetes mellitus(NIDDM) and hypertension, we used the atomic absorption spectrometry to detect Ca2+ and Mg2+ levels of serum and lymphocytes in patients with the above diseases. The results were that serum Ca2+ and Mg2+ levels had no change, but lymphocyte Ca2+ level increased obviously and lymphocyte Mg2+ level decreased obviously in both diseases, compared with normal controls. There were no difference between hypertension and NIDDM with and without hypertension. Ca2+ and Mg2+ levels of lymphocytes in patients with hypertension correlated with the systolic pressure respectively(Ca2+, r = 0.4633, P < 0.05; Mg2+, r = -0.4412, P < 0.05), but their levels in patients with NIDDM were not correlated with the fasting blood glucose. The results suggest that there is an abnormal Ca2+ and Mg2+ metabolism in lymphocytes in patients with hypertension and NIDDM.

Specific but variable expression of h-caldesmon in leiomyosarcomas: an immunohistochemical reassessment of a novel myogenic marker

h-Caldesmon is considered a novel specific marker for tumors with smooth muscle differentiation. To reassess its diagnostic use, the authors evaluated the immunohistochemical expression of h-caldesmon and other myogenic markers (calponin, alpha-smooth muscle actin, HHF35, and desmin) in 30 leiomyosarcomas (external soft tissues [15], retroperitoneum [8], uterus [5], other sites [2]), 26 myofibroblastic lesions, and 26 fibrohistiocytic tumors of varying biologic potential and histology. In contrast with previous data, h-caldesmon was expressed only in 11 (36%) of the 30 leiomyosarcomas analyzed, whereas they consistently expressed actins and frequently expressed calponin (86%) and desmin (76%). Leiomyosarcomas with the expression of h-caldesmon were well or moderately differentiated and primarily confined to the retroperitoneum or uterus. All but one leiomyosarcomas in the external soft tissues examined were negative for h-caldesmon, and the h-caldesmon-negative tumors showed moderately to poorly differentiated morphology. All myofibroblastic lesions examined were negative for h-caldesmon despite their constant expressions of at least one of the other markers. h-Caldesmon was not expressed in fibrohistiocytic tumors either, although focal positivity for the other markers was seen in subsets of the tumors. Thus, h-caldesmon can be regarded as a specific myogenic marker. However, one should be aware that the expression of h-caldesmon in leiomyosarcomas can be more variable according to their locations and/or extent of smooth muscle differentiation than considered previously.

New approach to phylogenetic analysis of the genus Bifidobacterium based on partial HSP60 gene sequences

The partial 60 kDa heat-shock protein (HSP60) genes of 36 Bifidobacterium strains representing 30 different Bifidobacterium species and subspecies and of the type strain of Gardnerella vaginalis were cloned and sequenced using a pair of universal degenerate HSP60 PCR primers. The HSP60 DNA sequence similarities were determined for the taxa at various ranks as follows: 99.4-100% within the same species, 96% at the subspecies level, and 73-96% (mean 85%) at the interspecies level (and 98% in the case of two groups of closely related species, Bifidobacterium animalis and Bifidobacterium lactis, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium suis, whose 165 rRNA sequence similarities are all above 99%). The HSP60 DNA sequence similarities between different Bifidobacterium species and G. vaginalis, a closely related bacterium according to 16S rRNA analysis, ranged from 71 to 79% (mean 75%). Although the topology of the phylogenetic tree constructed using the HSP60 sequences determined was basically similar to that for 16S rRNA, it seemed to be more clear-cut for species delineation, and the clustering was better correlated with the DNA base composition (mol% G+C) than that of the 16S rRNA tree. In the HSP60 phylogenetic tree, all of the high-G+C (55-67 mol%) bifidobacteria were grouped into one cluster, whereas the low-G+C species Bifidobacterium inopinatum (45 mol %) formed a separate cluster with G. vaginalis (42 mol%) and Bifidobacterium denticolens (55 mol%); a Bifidobacterium species of intermediate G+C content formed another cluster between the two. This study demonstrates that the highly conserved and ubiquitous HSP60 gene is an accurate and convenient tool for phylogenetic analysis of the genus Bifidobacterium.

An in vivo rat model for assessment of extrahepatic metabolism

INTRODUCTION

Xenobiotic metabolism in extrahepatic tissues has been extensively studied in vitro, but it is difficult to estimate in vivo the share of xenobiotic transformation in extrahepatic tissues for lack of a suitable approach. In this paper an in vivo rat model for assessment of extrahepatic metabolism is described, and the model was investigated using the conversion of lidocaine to monoethylglycinexylidide (MEGX).

METHODS

The rats were anesthetized with ethyl ether inhalation. The liver was exposed, the liver artery ligated, and the portal vein was clamped at its distal end. The left hepatic lobe was partly excised along its inferior margin, and a heparinized silicone catheter, diameter 0.2 cm, was inserted into the portal and left hepatic veins to allow the recirculation of portal vein blood. A sham operation was performed in the control group.

RESULTS

Phenol red test showed that hepatic blood supply was absolutely blocked in model rats. At 30 min after establishing the portal-cavum bypass, the renal function and electrolytes did not change, but serum glucose decreased by 64.4 +/- 30.4%; 30 min after intravenous administration of 1.0% lidocaine 2 mg x kg(-1), serum MEGX in model rats was 32.0 +/- 7.14% of that in the control group, which mostly existed in a free form and was not induced by phenobarbital pretreatment.

DISCUSSION

The model is easy to establish and provides an in vivo method to study the extrahepatic metabolism of xenobiotics.

Terpsichorean movements of pentaammineruthenium on pyrimidine and isocytosine ligands

Pentaammineruthenium moves on ambidentate nitrogen heterocycles by both rotation and linkage isomerization, which may affect the biological activity of potential ruthenium metallopharmaceuticals. The rapid rotation rates of [(NH3)5RuIII] coordinated to the exocyclic nitrogens of isocytosine (ICyt) and 6-methylisocytosine (6MeICyt) have been determined by 1H NMR. Since these rotamers can be stabilized by hydrogen bonding between the coordinated ammines and the N1 and N3 endocyclic nitrogens, rotamerization is under pH control. Spectrophotometrically (UV-vis) measured pKa values for the two endocyclic sites for the ICyt complex are 2.78 and 9.98, and for 6MeICyt are 3.06 and 10.21, which are probably weighted averages for ionization from N3 and N1, respectively. Activation parameters for the rotamerizations were determined by variable-temperature NMR at pKa1 < pH < pKa2 for the complexes with (ICyt-kappa N2)-, (6MeICyt kappa N2)-, and 2AmPym kappa N2. For [(6MeICyt kappa N2)(-)-(NH3)5RuIII]2+, delta H* = 1.6 kcal/mol, delta S* = -37 cal/mol K, and Ea = 2.2 kcal/mol. Due to strong RuIII-N pi-bonding, the activation enthalpies are approximately 10 kcal lower than the expected values for the free ligands. Rotameric structure is correlated with pKa values, pH-dependent reduction potentials, and 1H NMR parameters. Linkage isomers of [(2AmPym)(NH3)5Ru]n+ are reported in which RuII is coordinated to the endocyclic nitrogen (N1) and RuIII to the exocyclic nitrogen (N2). The rate constant for the kappa N2-->kappa N1 isomerization as part of an ECE mechanism is 3.9 s-1 at pH 3. The pH dependence of the acid-catalyzed hydrolysis of [(2AmPym kappa N1)(NH3)5Ru]2+ is determined.

The enhanced electrogenerated chemiluminescence of Ru(bpy)3(2+) by glutathione on a glassy carbon electrode modified with some porphine compounds

It has been found that the electrochemical activity of glutathione was increased greatly at the glassy carbon electrodes modified with 5,10,15,20-tetraphenylporphine ruthenium(II) carbenyl (RuTPP), meso-tetraphenylporphine copper(II) complex (CuTTP) and hemin. It has been also found that glutathione would enhance the electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) at a hemin glassy carbon electrode; the enhanced ECL intensity was linear with the concentration of glutathione in the range of 1 x 10(-7)-1 x 10(-4) mol l-1, based on which method for determination of glutathione has been developed. The detection limit of glutathione was 2 x 10(-8) mol l-1, and the relative standard deviation for 1 x 10(-6) mol l-1 glutathione was 2.7%. The mechanism for this ECL system has been proposed.

Simultaneous identification of five bifidobacterium species isolated from human beings using multiple PCR primers

On the basis of 16S rRNA sequences, 5 species-specific forward primers were designed for the identification of 5 Bifidobacterium species isolated from human intestine, namely B. bifidum, B. adolescentis, B. infantis, B. breve and B. longum. As the 5 primers targeted at different sites of 16S rDNA, by using their mixture and a genus-specific reversed primer, the 5 Bifidobacterium species can be simultaneously identified in individual or in mixed culture through PCR amplification. The specificity of the primers was confirmed by the use of genomic DNAs from type strains of all 32 Bifidobacterium species and 6 other relatives. The 5-primer mixture was also applied to the identification of Bifidobacterium strains used commercially. The results turned out to be in accordance with those from conventional identification. This multiple-primer method provides a useful tool for rapid identification of the 5 Bifidobacterium species indicated.

Bifidobacterium thermacidophilum sp. nov., isolated from an anaerobic digester

A new phenotypic group of Bifidobacterium strains, isolated from an anaerobic digester for the treatment of waste water from a bean-curd farm, was described previously. In this study, the DNA-DNA relatedness between strain 36 (type strain, AS 1.2282T) of this new group and the type strains of other described Bifidobacterium species was analysed. The low level of DNA homology (0-58.9%) as well as comparison of the 16S rDNA sequences confirmed the distinct phylogenetic position of strain 36. In addition, the new species differed from other Bifidobacterium species in its phenotypic characteristics, such as its growth at moderately thermophilic conditions (49.5 degrees C) and at relatively low pH (4.0), as well as its sugar-fermentation pattern. On the basis of phenotypic, genetic and phylogenetic studies, a new Bifidobacterium species, Bifidobacterium thermacidophilum sp. nov., was designated.

[A preliminary study of two Chinese herbs protective tablets on some Chinese traditional medicines]

The protective action of 2 tablets of Chinese herb to 5 Chinese traditional medicines against harm of insects and mildews was tested. It was found that 2 tablets have a obvious effects of insect-repellency and mouthproof in the test with Homalomena occulta and Prunus armeniaca, the bore in the medicinal materials was decreased 94.95% and 95.55% respectively than that of check. The tablets have some effects of mildewproof in the test with Tussilago farfara.

Mast cell regulation of human endometrial matrix metalloproteinases: A mechanism underlying menstruation

Endometrial matrix metalloproteinases (MMPs), which increase dramatically at menstruation, are purported to cause the focal tissue breakdown at menstruation, but how their expression or activation is locally regulated is unknown. Mast cell activation occurs within perimenstrual endometrium, and we postulated that mast cell products would regulate endometrial MMPs. We have examined the interaction between human mast cells and endometrial stromal cells with regard to MMP production and activation. The human mast cell line (HMC-1) in coculture with stromal cells stimulated stromal cell proMMP-1 and proMMP-3, and to a lesser extent proMMP-2 production, with increasing stimulation as mast cell number increased. Mast cell-conditioned medium also increased both protein and mRNA for stromal proMMP-1 and proMMP-3, this being abrogated by preadsorption of mast cell-conditioned medium with antisera to interleukin-1 and tumor necrosis factor alpha. Mast cell-conditioned medium added to stromal cell culture medium in vitro along with added heparin (which stabilizes tryptase activity) resulted in the appearance of molecular weight forms indicative of active MMP-3 and MMP-1. Thus activated mast cells within the endometrium prior to menstruation have the potential to stimulate MMP production by endometrial stromal cells and to initiate precursor activation, and are likely to account for the local nature of endometrial MMP action resulting in foci of tissue breakdown at menstruation.