NF-κB p65 and TCF-4 interactions are associated with LPS-stimulated IL-6 secretion of macrophages

Proinflammatory cytokine plays a central role in host defense and acute inflammatory responses. Both positive and negative correlations of NF-κB and Wnt/β-catenin pathways have been reported depending on cell types in response to inflammatory stimuli for IL-6 cytokine production. Macrophages are vital to the regulation of immune responses and the development of inflammation, but the crosstalk between two pathways has not been elucidated so far in macrophages. We observed a positive cross-regulation between the NF-κB and Wnt/β-catenin pathways for IL-6 production in human macrophages. To verify the functional validity of this interaction, LY294002 or PNU74654, representative blockers of each pathway, were treated. IL-6 secretion was reduced to the basal level by both inhibitor treatments, even when stimulated by LPS. We also found that NF-κB p65 migrated to the nucleus and interacted with the transcription factor TCF-4 in macrophages upon LPS stimulation.

BRAFV600E Mutation Enhances Estrogen-Induced Metastatic Potential of Thyroid Cancer by Regulating the Expression of Estrogen Receptors

BACKGRUOUND

Cross-talk between mitogen-activated protein kinase and estrogen has been reported; however, the role of BRAFV600E in the estrogen responsiveness of thyroid cancer is unknown. We elucidated the effect of BRAFV600E on the estrogen-induced increase in metastatic potential in thyroid cancer.

METHODS

Using a pair of cell lines, human thyroid cell lines which harbor wild type BRAF gene (Nthy/WT) and Nthy/BRAFV600E (Nthy/V600E), the expression of estrogen receptors (ERs) and estrogen-induced metastatic phenotypes were evaluated. Susceptibility to ERα- and ERβ-selective agents was evaluated to confirm differential ER expression. ESR expression was analyzed according to BRAFV600E status and age (≤50 years vs. >50 years) using The Cancer Genome Atlas (TCGA) data.

RESULTS

Estradiol increased the ERα/ERβ expression ratio in Nthy/V600E, whereas the decreased ERα/ERβ expression ratio was found in Nthy/WT. BRAFV600E-mutated cell lines showed a higher E2-induced increase in metastatic potential, including migration, invasion, and anchorage-independent growth compared with Nthy/WT. An ERα antagonist significantly inhibited migration in Nthy/V600E cells, whereas an ERβ agonist was more effective in Nthy/WT. In the BRAFV600E group, ESR1/ESR2 ratio was significantly higher in younger age group (≤50 years) compared with older age group (>50 years) by TCGA data analysis.

CONCLUSION

Our data show that BRAFV600E mutation plays a crucial role in the estrogen responsiveness of thyroid cancer by regulating ER expression. Therefore, BRAFV600E might be used as a biomarker when deciding future hormone therapies based on estrogen signaling in thyroid cancer patients.

Induction of BRAF^V600E Mutation in Thyroid Cells Leads to Frequent Hypermethylation

Objectives.

The BRAF^V600E mutation is a major driver mutation in papillary thyroid cancer. The aim of this study was to elucidate the correlation between DNA methylation and gene expression changes induced by the BRAF^V600E mutation in thyroid cells.

Methods.

We used Nthy/BRAF cell lines generated by transfection of Nthy/ori cells with the wild-type BRAF gene (Nthy/WT cells) and the V600E mutant-type BRAF gene (Nthy/V600E cells). We performed gene expression microarray and DNA methylation array analyses for Nthy/WT and Nthy/V600E cells. Two types of array data were integrated to identify inverse correlations between methylation and gene expression. The results were verified in silico using data from The Cancer Genome Atlas (TCGA) and in vivo through pyrosequencing and quantitative real-time polymerase chain reaction (qRT-PCR).

Results.

In the Nthy/V600E cells, 199,821 probes were significantly hypermethylated, and 697 genes showed a “hypermethylation-downregulation” pattern in Nthy/V600E. Tumor suppressor genes and apoptosis-related genes were included. In total, 66,446 probes were significantly hypomethylated, and 227 genes showed a “hypomethylation-upregulation” pattern in Nthy/V600E cells. Protooncogenes and developmental protein-coding genes were included. In the TCGA analysis, 491/697 (70.44%) genes showed a hypermethylation-downregulation pattern, and 153/227 (67.40%) genes showed a hypomethylation-upregulation pattern. Ten selected genes showed a similar methylation-gene expression pattern in pyrosequencing and qRT-PCR.

Conclusion.

Induction of the BRAF^V600E mutation in thyroid cells led to frequent hypermethylation. Anticancer genes, such as those involved in tumor suppression or apoptosis, were downregulated by upstream hypermethylation, whereas carcinogenic genes, such as protooncogenes, were upregulated by hypomethylation. Our results suggest that the BRAF^V600E mutation in thyroid cells modulates DNA methylation and results in cancer-related gene expression.

BRAFV600E Transduction of an SV40-Immortalized Normal Human Thyroid Cell Line Induces Dedifferentiated Thyroid Carcinogenesis in a Mouse Xenograft Model

Background: Despite active studies of the clinical importance of BRAF^V600E, suitable research models to investigate the role of this mutation in the etiopathogenesis of human thyroid cancers are limited. Thus, we generated cell lines by transducing the simian virus (SV)-40 immortalized human thyroid cell line Nthy-ori 3-1 (Nthy) with lentiviral vectors expressing either BRAF^WT (Nthy/WT) or BRAF^V600E. Nthy/WT and Nthy/V600E cells were then xenografted into mice to evaluate the carcinogenic role of BRAF^V600E. Methods: Each cell line was subcutaneously injected into NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ mice, and a pathological analysis was performed. The effects of the mutation were further verified by using a BRAF^V600E-selective inhibitor (PLX-4032, vemurafenib). The transcriptome was analyzed by RNA sequencing and compared with data from The Cancer Cell Line Encyclopedia and Gene Expression Omnibus. Results: While Nthy/WT was not tumorigenic in vivo, Nthy/V600E formed tumors reaching 2784.343 mm³ in 4 weeks, on average. A pathological analysis indicated that Nthy/V600E tumors were dedifferentiated thyroid cancer. We found metastases in the lung, liver, and relevant lymph nodes. A transcriptomic analysis revealed 5512 differentially expressed genes (DEGs) between the mutant and wild-type cell lines, and more DEGs were shared with anaplastic thyroid cancer than with papillary thyroid cancer. BRAF^V600E activated the cell cycle mainly by regulating G1/S phases. PLX-4032 treatment significantly inhibited tumor growth and metastasis. Conclusions: Our data show that BRAF^V600E plays a pivotal role in the carcinogenic transformation of an SV40-transfected immortalized normal human thyroid cell line. This xenograft model is expected to contribute to studies of the etiopathogenesis and treatment of highly malignant thyroid cancers.

Refractory healing after surgical therapy of osteonecrosis of the jaw: associated risk factors in aged patients

Purpose: Osteonecrosis of the jaw (ONJ), both medication-related and non medication-related, mainly occurs in aged patients. It needs surgical intervention. Refractory healing after an operation of ONJ can significantly lower the quality of life of elderly patients. The purpose of this study was to determine risk factors associated with refractory healing in aged patients.

Patients and methods: We performed a retrospective study of ONJ in aged patients who underwent surgical treatments in a single institute during a 12-year period. Multiple logistic regression analysis was used to determine independent risk factors associated with refractory healing.

Results: A total of 122 patients were included. Of them, 25 patients were identified as the refractory group and 97 patients as the control group. Diabetes mellitus (DM) (AOR=5.03, 95% CI: 1.74–14.52) and glucocorticoid administration (AOR=7.97, 95% CI: 2.52–25.23) were found to be significant risk factors for refractory healing of ONJ.

Conclusion: DM and medication of glucocorticoid might be risk factors for refractory healing of ONJ.

Expression of SLC5A5 in Circulating Tumor Cells May Distinguish Follicular Thyroid Carcinomas from Adenomas: Implications for Blood-Based Preoperative Diagnosis

Preoperative diagnosis of thyroid nodules reduces unnecessary surgery. Circulating tumor cells (CTCs) may contain information of primary tumor(s). We asked whether the peripheral blood expression of genes specific for circulating tumor cells (CTCs) differentiates benign thyroid nodules from malignant nodules. Peripheral blood mononuclear cells from thyroid nodule patients (n = 20) were isolated preoperatively and the expression of seven CTC-associated genes was measured in patients with thyroid nodule(s) (n = 20). Among the tested genes, the expression of SLC5A5 and LGALS3 were validated in a larger number of patients (n = 64) and our results show that SLC5A5 expression differentiated follicular adenomas from follicular carcinomas (area under the curve (AUC) = 0.831). The expression of SLC5A5 in CTCs may preoperatively distinguish thyroid follicular adenomas from follicular carcinomas.

CRISPR RNAs trigger innate immune responses in human cells

Here, we report that CRISPR guide RNAs (gRNAs) with a 5'-triphosphate group (5'-ppp gRNAs) produced via in vitro transcription trigger RNA-sensing innate immune responses in human and murine cells, leading to cytotoxicity. 5'-ppp gRNAs in the cytosol are recognized by DDX58, which in turn activates type I interferon responses, causing up to ∼80% cell death. We show that the triphosphate group can be removed by a phosphatase in vitro and that the resulting 5'-hydroxyl gRNAs in complex with Cas9 or Cpf1 avoid innate immune responses and can achieve targeted mutagenesis at a frequency of 95% in primary human CD4+ T cells. These results are in line with previous findings that chemically synthesized sgRNAs with a 5'-hydroxyl group are much more efficient than in vitro-transcribed (IVT) sgRNAs in human and other mammalian cells. The phosphatase treatment of IVT sgRNAs is a cost-effective method for making highly active sgRNAs, avoiding innate immune responses in human cells.

Expression Profiling of a Human Thyroid Cell Line Stably Expressing the BRAFV600E Mutation

BACKGROUND/AIM

The BRAF^V600E mutation acts as an initiator of cancer development in papillary thyroid carcinoma (PTC). Gene expression changes caused by the BRAF^V600E mutation may have an important role in thyroid cancer development.

MATERIALS AND METHODS

To study genomic alterations caused by the BRAF^V600E mutation, we made human thyroid cell lines that harbor the wild-type BRAF gene (Nthy/WT) and the V600E mutant-type BRAF gene (Nthy/V600E).

RESULTS

Flow cytometry and western blotting showed stable transfection of the BRAF gene. In functional experiments, Nthy/V600E showed increased anchorage-independent growth and invasion through Matrigel, compared to Nthy/WT. Microarray analysis revealed that 2,441 genes were up-regulated in Nthy/V600E compared to Nthy/WT. Gene ontology analysis showed that the up-regulated genes were associated with cell adhesion, migration, and the ERK and MAPK cascade, and pathway analysis showed enrichment in cancer-related pathways.

CONCLUSION

Our Nthy/WT and Nthy/V600E cell line pair could be a suitable model to study the molecular characteristics of BRAF^V600E PTC.

Viral RNA in Blood as Indicator of Severe Outcome in Middle East Respiratory Syndrome Coronavirus Infection

We evaluated the diagnostic and clinical usefulness of blood specimens to detect Middle East respiratory syndrome coronavirus infection in 21 patients from the 2015 outbreak in South Korea. Viral RNA was detected in blood from 33% of patients at initial diagnosis, and the detection preceded a worse clinical course.

Significance of the BRAF mRNA Expression Level in Papillary Thyroid Carcinoma: An Analysis of The Cancer Genome Atlas Data

Background

BRAF^V600E is the most common mutation in papillary thyroid carcinoma (PTC), and it is associated with high-risk prognostic factors. However, the significance of the BRAF mRNA level in PTC remains unknown. We evaluated the significance of BRAF mRNA expression level by analyzing PTC data from The Cancer Genome Atlas (TCGA) database.

Methods

Data from 499 patients were downloaded from the TCGA database. After excluding other PTC variants, we selected 353 cases of classic PTC, including 193 cases with BRAF^V600E and 160 cases with the wild-type BRAF. mRNA abundances were measured using RNA-Seq with the Expectation Maximization algorithm.

Results

The mean BRAF mRNA level was significantly higher in BRAF^V600E patients than in patients with wild-type BRAF (197.6 vs. 179.3, p = 0.031). In wild-type BRAF patients, the mean BRAF mRNA level was higher in cases with a tumor > 2 cm than those with a tumor ≤ 2.0 cm (189.4 vs. 163.8, p = 0.046), and was also higher in cases with lymph node metastasis than in those without lymph node metastasis (188.5 vs. 157.9, p = 0.040). Within BRAF^V600E patients, higher BRAF mRNA expression was associated with extrathyroidal extension (186.4 vs. 216.4, p = 0.001) and higher T stage (188.1 vs. 210.2, p = 0.016).

Conclusions

A higher BRAF mRNA expression level was associated with tumor aggressiveness in classic PTC regardless of BRAF mutational status. Evaluation of BRAF mRNA level may be helpful in prognostic risk stratification of PTC.

Immune parameters differentiating active from latent tuberculosis infection in humans

Tuberculosis remains a highly prevalent infectious disease worldwide. Identification of the immune parameters that differentiate active disease from latent infection will facilitate the development of efficient control measures as well as new diagnostic modalities for tuberculosis. Here, we investigated the cytokine production profiles of monocytes and CD4(+) T lymphocytes upon encountering mycobacterial antigens. In addition, cytokines and lipid mediators with immune-modulating activities were examined in plasma samples ex vivo. Comparison of these parameters in active tuberculosis patients and healthy subjects with latent infection revealed that, active tuberculosis was associated with diminished Th1-type cytokine secretion from CD4(+) T cells and less augmented inflammatory cytokine secretion from monocytes induced by IFN-γ than that in latent tuberculosis infection. In addition, a higher plasma concentration of lipoxin A4 and lower ratio of prostaglandin E2 to lipoxin A4 were observed in active cases than in latent infections. These findings have implications for preparing new therapeutic strategies and for differential diagnosis of the two types of tuberculosis infection.

Combined effect of Hashimoto's thyroiditis and BRAF(V600E) mutation status on aggressiveness in papillary thyroid cancer

BACKGROUND

The purpose of this study was to evaluate the association between Hashimoto's thyroiditis and BRAF(V600E) mutation status in patients with papillary thyroid cancer (PTC) and to determine their combined association with tumor aggressiveness in PTC.

METHODS

A total of 1780 patients with PTC who underwent surgery were enrolled in this study. Simple and multiple analyses were performed to determine the association between Hashimoto's thyroiditis and the BRAF(V600E) mutation in PTC.

RESULTS

Hashimoto's thyroiditis was present in 11.5% of patients (204/1780) with PTC. Multiple logistic regressions showed that BRAF(V600E) (odds ratio [OR] = 0.493; 95% confidence interval [CI] = 0.360-0.678) and the female sex (OR = 7.146; 95% CI = 3.408-18.347) were independent factors associated with Hashimoto's thyroiditis in PTC. BRAF(V600E) mutation and the Hashimoto's thyroiditis-negative PTC group were associated with aggressive disease (OR = 3.069; 95% CI = 1.654-5.916).

CONCLUSION

Hashimoto's thyroiditis was associated less frequently with BRAF(V600E) , and frequently with the female sex in patients with PTC. Hashimoto's thyroiditis and BRAF(V600E) status may help to predict clinical outcome of PTC.

Differential expression of CD57 in antigen-reactive CD4+ T cells between active and latent tuberculosis infection

The development of diagnostic tests that predict the progression of latent tuberculosis infection to active disease is pivotal for the eradication of tuberculosis. As an initial step to achieve this goal, our study's aim was to identify biomarkers that differentiate active from latent tuberculosis infection. We compared active and latent tuberculosis infection groups in terms of the precursor frequency, functional subset differentiation, and senescence/exhaustion surface marker expression of antigen-specific CD4(+) T cells, which were defined as dividing cells upon their encountering with Mycobacterium (M.) tuberculosis antigens. Among several parameters shown to have statistically significant differences between the two groups, the frequency of CD57-expressing cells could differentiate effectively between active disease and latent infection. Our results suggest that the expression of CD57 in M. tuberculosis-reactive CD4(+) T cells could be a promising candidate biomarker with which to identify individuals with latent tuberculosis infection prone to progression to active disease.

Expression of the embryonic morphogen Nodal in differentiated thyroid carcinomas: Immunohistochemistry assay in tissue microarray and The Cancer Genome Atlas data analysis

BACKGROUND

Nodal, an embryonic morphogen, plays a role in tumorigenesis of melanoma, breast, and prostate cancer; however, its role in thyroid carcinoma is unknown. We examined Nodal expression in thyroid tumors by immunohistochemistry assay and The Cancer Genome Atlas (TCGA) analysis.

METHODS

An immunohistochemistry assay was performed in a tissue microarray comprising 128 classic papillary thyroid carcinomas (PTC), 58 follicular thyroid carcinomas (FTC), 19 follicular variants of PTC (FVPTC), 57 follicular adenomas (FA), 54 adenomatous goiters (AG), and 5 normal thyroid tissues. The TCGA database was examined to evaluate the expression of Nodal mRNA in normal thyroid and PTC.

RESULTS

The proportion of tumors showing negative Nodal expression in PTC, FTC, FVPTC, FA, and AG was 0%, 1.7%, 0%, 14%, and 41%, respectively. For the diagnosis of malignant tumors, the sensitivity, specificity, positive predictive value, and negative predictive value of positive Nodal staining was 99%, 27%, 72%, and 97%, respectively. High Nodal expression was associated with older age and BRAF mutation in PTC. TCGA analysis revealed PTC had greater Nodal mRNA expression than normal thyroid (P = .012).

CONCLUSION

Nodal staining might be useful "rule-out test" for the diagnosis of malignant thyroid tumor. Nodal may be associated with the tumorigenesis of thyroid malignancy.

JNK signaling in hepatocarcinoma cells is associated with the side population upon treatment with anticancer drugs

Liver cancer is one of the most drug-resistant cancer types, and cancer stem cells are related to drug resistance. c-Jun-N-terminal kinase (JNK) signaling is involved in drug resistance, and the side population of cells (SP cells) can be used as a model to study liver cancer stem cells. We sought to evaluate the relationship between SP cells and JNK signaling in hepatocarcinoma cells. For this purpose, we examined cell proliferation and the SP cell ratio following treatment of Huh7 cells with the anticancer drugs 5-fluorouracil (5-FU) and paclitaxel. The expression of phospho-stress-activated protein kinase (SAPK)/JNK in the treated cells was evaluated using immunoblotting. 5-FU and paclitaxel treatment increased the number of SP cells and JNK phosphorylation, and decreased cell survival. Huh7 and HepG2 cells were also treated with SP600125, a JNK inhibitor, to study the relationship between SP cells and JNK signaling. The increase in the number of SP cells and the SAPK/JNK and c-Jun phosphorylation was reverted by SP600125 treatment in these cells. We also used immunohistochemistry and showed that SAPK/JNK and c-Jun phosphorylation are increased in hepatocarcinoma tissues. In conclusion, our results demonstrate that the number of SP cells and SAPK/JNK phosphorylation are increased upon treatment with anticancer drugs, and that this increase is blocked by inhibition of JNK signaling. These findings suggest that drug resistance in liver cancer may involve an increase in the number of SP cells following JNK activation.

Abstract 3416: Transcriptome analysis of papillary thyroid cancer using next-generation sequencing technologies in Korean patients

Thyroid cancer is one of the most prevalent cancers worldwide, and papillary thyroid cancer (PTC) accounts for >80% of all thyroid cancers. Here we conducted RNA sequencing for 70 PTC and 42 paired-normal tissues in Korean patients, and their transcriptomes were analyzed in various aspects. First, somatic mutations were screened transcriptome-wide throughout samples; BRAF mutation (V600E), which is the most well-established mutation in thyroid cancer, was detected in 47 samples out of 70 (67.14%). HRAS (Q61R, Q61K) and NRAS (Q61R) mutations were shown in two samples, respectively. In gene fusion analysis, we discovered four fusion mutations using our stringent criteria and these include CCDC6-RET and PAX8-PPARG fusions, which have been previously reported for thyroid cancer. Other EZR-ERBB4 and PAX8-GLIS3 fusions are novel fusion mutations found in PTC, and the sample having EZR-ERBB4 mutation was diagnosed as the follicular variant subtype. This is an in-frame mutation and previous reports have shown that ERBB4 is a driver gene for carcinogenesis in multiple types of cancers. In addition, we also found ETV6-NTRK3 fusion in less conservative criteria, which was a well-known fusion in other cancer types. Each fusion mutation above was shown in only one sample, respectively. Through gene expression analysis, we clustered PTC cancer samples into four groups; three of them are shown to be enriched with BRAF V600E mutation, and the other includes samples with NRAS, HRAS mutation. In this study, we thoroughly explored the transcriptome of PTC samples using the next-generation sequencing method and proved well-correlation between mutation and expression profiles. These results not only replicated several findings of previous studies and suggested some novel genes or pathways involved in the PTC development in Koreans.

Citation Format: Seungbok Lee, Hyeon-Gun Jee, Kyu Eun Lee, Jeong-Sun Seo. Transcriptome analysis of papillary thyroid cancer using next-generation sequencing technologies in Korean patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3416. doi:10.1158/1538-7445.AM2014-3416

Side population in LX2 cells decreased by transforming growth factor-β

AIM

Side population (SP) cells are known to be enriched in stem/progenitor-like cells. Transforming growth factor (TGF)-β signaling is associated with extracellular matrix (ECM) production in hepatic stellate cells. We hypothesized that the SP fraction in LX2 cells is associated with ECM deposition, which is regulated through TGF-β signaling.

METHODS

We investigated the relationship between SP cells and TGF-β signaling in the hepatic stellate cell line LX2. The effects of TGF-β and SB431542 on the SP fraction and expression of collagen type I and phospho-Smad2 was determined.

RESULTS

We identified 0.8-3% SP cells in LX2 cells. The growth rate of sorted SP and non-SP cells was similar to that of the original LX2 population, but population of the G0/G1 phase was increased in SP cells. Treatment of LX2 cells with TGF-β decreased the SP fraction in a dose-dependent manner and increased the production of collagen type I. Treatment of LX2 cells with SB431542 blocked the effect of TGF-β on the SP fraction and the expression of collagen type I. We cultured LX2 cells on collagen-coated dishes to observe the effect of ECM deposition on the SP fraction. The growth rate and cell cycle distribution was similar to that observed on normal tissue culture dishes, but the SP fraction was decreased when LX2 cells were cultured on collagen-coated plates.

CONCLUSION

These results show that LX2 cells contain an SP fraction and that TGF-β signaling is involved in the induction of ECM deposition as well as the number of SP cells.

Berberine inhibited the growth of thyroid cancer cell lines 8505C and TPC1

PURPOSE

Thyroid cancer is the most common malignancy in Korean females and can be treated with good prognosis. However, drugs to treat aggressive types of thyroid cancer such as poorly differentiated or anaplastic thyroid cancer have not yet been established. To that end, we analyzed the effects of berberine on human thyroid cancer cell lines to determine whether this compound is useful in the treatment of aggressive thyroid cancer.

MATERIALS AND METHODS

The two thyroid cancer cell lines 8505C and TPC1, under adherent culture conditions, were treated with berberine and analyzed for changes in cell growth, cell cycle duration, and degree of apoptosis.

RESULTS

Following berberine treatment, both cell lines showed a dose-dependent reduction in growth rate. 8505C cells showed significantly increased levels of apoptosis following berberine treatment, whereas TPC1 cells showed cell cycle arrest at the G0/G1 phase. Immunobloting of p-27 expression following berberine treatment showed that berberine induced a little up-regulation of p-27 in 8505c cells but relatively high up-regulation of p-27 in TPC1 cells.

CONCLUSION

These results suggest that berberine treatment of thyroid cancer can inhibit proliferation through apoptosis and/or cell cycle arrest. Thus, berberine may be a novel anticancer drug for the treatment of poorly differentiated or anaplastic thyroid cancer.

Is there a treatment advantage when paclitaxel and lovastatin are combined to dose anaplastic thyroid carcinoma cell lines?

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid carcinoma. The purpose of this study was to evaluate the combined cytotoxic effects of paclitaxel and lovastatin in ATC cell lines.

METHODS

ATC cells were treated with paclitaxel and lovastatin, separately or together, and the cytotoxicity of the compounds was determined by quantifying cell viability and apoptosis. We conducted an isobologram analysis to investigate the combined effect of the two drugs.

RESULTS

In 8505C cells, cellular viability was inhibited by lovastatin and paclitaxel in a concentration-dependent manner (p = 0.002 and p = 0.020, respectively). The IC(50) of lovastatin was 3.53 μM and that of paclitaxel was 5.98 nM. In BHT-101 cells, cellular viability was also inhibited in a concentration-dependent manner by lovastatin and paclitaxel (p = 0.020 and p = 0.032, respectively). The IC(50) of lovastatin was 17.13 μM and that of paclitaxel was 35.26 nM. In 8505C cells, paclitaxel and lovastatin alone induced apoptosis in a concentration-dependent manner. However, both an isobologram analysis on inhibition of viability and an analysis of apoptosis demonstrated antagonism between paclitaxel and lovastatin. In BHT-101 cells, however, neither drug had an apoptotic effect when used individually. There was a variable effect when used in combination, depending on the drug concentrations.

CONCLUSIONS

Paclitaxel and lovastatin were cytotoxic in two ATC cell lines and increased apoptosis in 8505C cells. However, in these cells, the combination of drugs resulted in antagonism that affected both the cytotoxicity of the compounds and the apoptosis of 8505C cells. The combination of paclitaxel and lovastatin did not enhance the treatment effect in ATC cell lines.

CD24 cross-linking induces apoptosis in, and inhibits migration of, MCF-7 breast cancer cells

Background

The biological effects of CD24 (FL-80) cross-linking on breast cancer cells have not yet been established. We examined the impact of CD24 cross-linking on human breast cancer cell line MCF-7.

Methods

MCF-7 and MDA-MB-231 cells were treated with anti-rabbit polyclonal IgG or anti-human CD24 rabbit polyclonal antibodies to induce cross-linking, and then growth was studied. Changes in cell characteristics such as cell cycle modulation, cell death, survival in three-dimensional cultures, adhesion, and migration ability were assayed after CD24 cross-linking in MCF-7.

Results

Expression of CD24 was analyzed by flow cytometry in MDA-MB-231 and MCF-7 cells where 2% and 66% expression frequencies were observed, respectively. CD24 cross-linking resulted in time-dependent proliferation reduction in MCF-7 cells, but no reduction in MDA-MB-231 cells. MCF-7 cell survival was reduced by 15% in three-dimensional culture after CD24 cross-linking. Increased MCF-7 cell apoptosis was observed after CD24 cross-linking, but no cell cycle arrest was observed in that condition. The migration capacity of MCF-7 cells was diminished by 30% after CD24 cross-linking.

Conclusion

Our results showed that CD24 cross-linking induced apoptosis and inhibited migration in MCF-7 breast cancer cells. We conclude that CD24 may be considered as a novel therapeutic target for breast cancer.

Transmission of scrub typhus by needlestick from a patient receiving pefloxacin

A nurse experience a needlestick during the care of a patient with scrub typhus, treated with pefloxacin (400 mg twice daily) and cefazolin. Seven days after the needlestick, pain and erythematous swelling developed at the tip of her left fourth finger, the site of the needlestick. Fever and headache developed 10 days later, and her skin lesion became a small vesicle surrounded by a dark erythematous area. The diagnosis of scrub typhus was made by a rising indirect immunofluorescent antibody titre, and her illness was improved with doxycycline.