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1.
Diagnostics (Basel) ; 14(12)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38928624

ABSTRACT

Screening for osteoporosis is crucial for early detection and prevention, yet it faces challenges due to the low accuracy of calcaneal quantitative ultrasound (QUS) and limited access to dual-energy X-ray absorptiometry (DXA) scans. Recent advances in AI offer a promising solution through opportunistic screening using existing medical images. This study aims to utilize deep learning techniques to develop a model that analyzes chest X-ray (CXR) images for osteoporosis screening. This study included the AI model development stage and the clinical validation stage. In the AI model development stage, the combined dataset of 5122 paired CXR images and DXA reports from the patients aged 20 to 98 years at a medical center was collected. The images were enhanced and filtered for hardware retention such as pedicle screws, bone cement, artificial intervertebral discs or severe deformity in target level of T12 and L1. The dataset was then separated into training, validating, and testing datasets for model training and performance validation. In the clinical validation stage, we collected 440 paired CXR images and DXA reports from both the TCVGH and Joy Clinic, including 304 pared data from TCVGH and 136 paired data from Joy Clinic. The pre-clinical test yielded an area under the curve (AUC) of 0.940, while the clinical validation showed an AUC of 0.946. Pearson's correlation coefficient was 0.88. The model demonstrated an overall accuracy, sensitivity, and specificity of 89.0%, 88.7%, and 89.4%, respectively. This study proposes an AI model for opportunistic osteoporosis screening through CXR, demonstrating good performance and suggesting its potential for broad adoption in preliminary screening among high-risk populations.

2.
Front Surg ; 9: 911514, 2022.
Article in English | MEDLINE | ID: mdl-36061052

ABSTRACT

Oblique lumbar interbody fusion (OLIF) is a popular technique for the treatment of degenerative lumbar spinal disease. There are no clear guidelines on whether direct posterior decompression (PD) is necessary after OLIF. The purpose of this study was to analyze the effect of the indirect decompression obtained from OLIF in patients with lumbar foraminal stenosis. We retrospectively reviewed 33 patients who underwent OLIF surgery for degenerative lumbar spinal disease between 1 January 2018, and 30 June 2019. The inclusion criteria included patients who were diagnosed with lumbar foraminal stenosis by preoperative MRI. The exclusion criteria included the presence of central canal stenosis, spinal infection, vertebral fractures, and spinal malignancies. The clinical results, evaluated using the visual analogue scale of back pain (VAS-Back), VAS of leg pain (VAS-Leg), and Oswestry disability index (ODI), were recorded. The radiologic parameters were also measured. The VAS-Back, VAS-Leg, and ODI showed significant improvement in both the PD and non-posterior decompression (Non-PD) groups postoperatively (all, p < 0.05). Patients in the Non-PD group showed better results than those in the PD group in the VAS-Back at 12- and 24 months postoperatively (0.00 vs. 3.00 postoperatively at 12 months, p = 0.030; 0.00 vs. 4.00 postoperatively at 24 months, p = 0.009). In addition, the ODI at 24 months postoperatively showed better improvement in the Non-PD group (8.89 vs. 24.44, p = 0.038). The disc height in both the PD and the Non-PD groups increased significantly postoperatively (all, p < 0.05), but the restoration of foraminal height was significantly different only in the Non-PD group. There was no statistically significant difference in cage position, cage subsidence, fusion grade, or screw loosening between the PD and the Non-PD groups. Indirect decompression via OLIF for lumbar foraminal stenosis showed favorable outcomes. The use of interbody cages and posterior instrumentation was sufficient for relieving symptoms in patients with lumbar foraminal stenosis. Additional direct posterior decompression may deteriorate results in the follow-up period.

3.
J Clin Med ; 10(22)2021 Nov 22.
Article in English | MEDLINE | ID: mdl-34830729

ABSTRACT

Spinal fusion surgery for end-stage renal disease (ESRD) patients is a clinical challenge. This study aimed to investigate whether postoperative radiological outcomes are related to preoperative serum calcium, phosphate, or intact parathyroid hormone (iPTH) levels in patients with ESRD who underwent spinal interbody fusion surgery. This study included 62-consecutive patients with ESRD who underwent anterior cervical discectomy and fusion (ACDF) or transforaminal lumbar interbody fusion (TLIF) surgery for symptomatic spinal disorder. The most recent preoperative serum calcium, phosphate, and iPTH levels were recorded, and the postoperative radiographic outcomes were assessed. A significant correlation was found between the occurrence of cage subsidence and higher blood phosphate, calcium-phosphate product (Ca × P), and iPTH levels in the TLIF group. The occurrence of pedicle screw loosening was related to higher blood phosphate and Ca × P product in the TLIF group. However, no correlation was found between the fusion grades and the serum levels in either the TLIF or ACDF groups. These results indicated that higher preoperative serum phosphate and Ca × P product are risk factors for both cage subsidence and screw loosening in patients with ESRD who underwent TLIF surgery. Higher iPTH levels are also a possible risk factor for cage subsidence.

4.
BMC Cancer ; 20(1): 386, 2020 May 06.
Article in English | MEDLINE | ID: mdl-32375699

ABSTRACT

BACKGROUND: According to GLOBOSCAN, hepatocellular carcinoma (HCC) claimed 782,000 lives in 2018. The tyrosine kinase inhibitor sofafenib is used to treat HCC, but new anticancer agents targeting different pathways are urgently needed to improve outcomes for patients with advanced disease. The aberrant metabolism and aggressive growth of cancer cells can render them particularly susceptible to proteasome inhibition, as demonstrated by bortezomib treatment of multiple myeloma. However, resistance does emerge, and this 20S proteasome inhibitor has not proven active against HCC. The bis-benzylidine piperidone RA190 represents a novel class of proteasome inhibitor that covalently binds to cysteine 88 of RPN13, an ubiquitin receptor subunit of the proteasome's 19S regulatory particle. RA190 treatment inhibits proteasome function, causing rapid accumulation of polyubiquitinated proteins. Considerable evidence suggests that nuclear factor κB (NF-κB) signaling, which is dependent upon the proteasome, is a major driver of inflammation-associated cancers, including HCC. METHODS: Human HCC cell lines were treated with titrations of RA190. The time course of endoplasmic reticulum stress and NF-κB-related mechanisms by which RA190 may trigger apoptosis were assessed. The therapeutic activity of RA190 was also determined in an orthotopic HCC xenograft mouse model. RESULTS: RA190 is toxic to HCC cells and synergizes with sofafenib. RA190 triggers rapid accumulation of polyubiquitinated proteins, unresolved endoplasmic reticulum stress, and cell death via apoptosis. RA190 blocks proteasomal degradation of IκBα and consequent release of NF-κB into the nuclei of HCC cells. Treatment of mice bearing an orthotopic HCC model with RA190 significantly reduced tumor growth. CONCLUSIONS: RA190 has therapeutic activity in a xenograft model, and with sorafenib exhibited synergetic killing of HCC cells in vitro, suggesting further exploration of such a combination treatment of HCC is warranted.


Subject(s)
Antineoplastic Agents/pharmacology , Benzylidene Compounds/pharmacology , Carcinoma, Hepatocellular/drug therapy , Gene Expression Regulation, Neoplastic/drug effects , Intracellular Signaling Peptides and Proteins/metabolism , Liver Neoplasms/drug therapy , NF-kappa B/antagonists & inhibitors , Animals , Apoptosis , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Proliferation , Endoplasmic Reticulum Stress/drug effects , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Tumor Cells, Cultured , Ubiquitin/metabolism , Ubiquitination , Xenograft Model Antitumor Assays
5.
Exp Cell Res ; 322(2): 345-54, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24530475

ABSTRACT

Elevated heat shock protein 90 (Hsp90) expression has been linked to poor prognosis in patients with non-small cell lung cancer (NSCLC). The multitargeted antifolate pemetrexed has demonstrated certain clinical activities against NSCLC. However, the efficacy of the combination of pemtrexed and Hsp90 inhibitor to prolong the survival of patients with NSCLC still remains unclear. Human MutS homolog 2 (MSH2), a crucial element of the highly conserved DNA mismatch repair system, and defects or polymorphisms of MSH2 have been found in lung cancer. In this study, we evaluated the effects of pemetrexed on NSCLC cell lines (H520 and H1703) and found that treatment with this drug at 20-50 µM increased the MSH2 mRNA and protein levels in a MKK3/6-p38 MAPK signal activation-dependent manner. Furthermore, the knockdown of MSH2 expression by transfection with small interfering RNA of MSH2 or the blockage of p38 MAPK activation by SB202190 enhanced the cytotoxicity of pemetrexed. Combining the drug treatment with an Hsp90 inhibitor resulted in an enhanced pemetrexed-induced cytotoxic effect, accompanied with the reduction of MSH2 protein and mRNA levels. The expression of constitutively active MKK6 (MKK6E) or HA-p38 MAPK vectors significantly rescued the decreased p38 MAPK activity, and restored the MSH2 protein levels and cell survival in NSCLC cells co-treated with pemetrexed and Hsp90 inhibitor. In this study, we have demonstrated that down-regulation of the MKK3/6-p38 MAPK signal with the subsequent reduction of MSH2 enhanced the cytotoxic effect of pemetrexed in H520 and H1703 cells. The results suggest a potential future benefit of combining pemetrexed and the Hsp90 inhibitor to treat lung cancer.


Subject(s)
Apoptosis/drug effects , Carcinoma, Non-Small-Cell Lung/pathology , Drug Resistance, Neoplasm , Gene Expression Regulation, Neoplastic/drug effects , Glutamates/pharmacology , Guanine/analogs & derivatives , HSP90 Heat-Shock Proteins/antagonists & inhibitors , MutS Homolog 2 Protein/metabolism , Antineoplastic Agents/pharmacology , Blotting, Western , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Proliferation/drug effects , Enzyme Inhibitors/pharmacology , Guanine/pharmacology , Humans , Imidazoles/pharmacology , Immunoprecipitation , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , MutS Homolog 2 Protein/antagonists & inhibitors , MutS Homolog 2 Protein/genetics , Pemetrexed , Pyridines/pharmacology , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Tumor Stem Cell Assay , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
6.
Lung Cancer ; 82(3): 397-406, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24138903

ABSTRACT

OBJECTIVES: Gefitinib, a quinazoline-derived tyrosine kinase inhibitor, has anti-tumor activity in vivo and in vitro. Human MutS homologue-2 (MSH2) plays a central role in promoting genetic stability by correcting DNA replication errors. The present study investigated the effects of p38 mitogen-activated protein kinase (MAPK) signal on gefitinib-induced MSH2 expression in two human non-small cell lung squamous cancer cell lines. MATERIALS AND METHODS: After the gefitinib treatment, the expressions of MSH2 mRNA were determined by real-time PCR and RT-PCR analysis. Protein levels of MSH2, phospho-MKK3/6, phospho-p38 MAPK were determined by Western blot analysis. We used specific MSH2, and p38 MAPK small interfering RNA to examine the role of p38 MAPK-MSH2 signal in regulating the chemosensitivity of gefitinib. Cell viability was assessed by MTS assay, trypan blue exclusion, and colony-forming ability assay. RESULTS: Exposure of gefitinib increased MSH2 protein and mRNA levels, which was accompanied by MKK3/6-p38 MAPK activation in H520 and H1703 cells. Moreover, blocking p38 MAPK activation by SB202190 significantly decreased gefitinib-induced MSH2 expression by increasing mRNA and protein instability. In contrast, enhancing p38 activation using constitutively active MKK6 (MKK6E) increased MSH2 protein and mRNA levels. Specific inhibition of MSH2 expression by siRNA enhanced gefitinib-induced cytotoxicity. Metformin, an anti-diabetic drug, might reduce cancer risk. In human lung squamous cancer cells, metformin decreased gefitinib-induced MSH2 expression and augmented the cytotoxic effect and growth inhibition by gefitinib. Transient expression of MKK6E or HA-p38 MAPK vector could abrogate metformin and gefitinib-induced synergistic cytotoxic effect in H520 and H1703 cells. CONCLUSION: Together, down-regulation of MSH2 expression can be a possible strategy to enhance the sensitivity of gefitinib to human lung squamous cancer cells.


Subject(s)
Carcinoma, Squamous Cell/drug therapy , Lung Neoplasms/drug therapy , Metformin/pharmacology , MutS Homolog 2 Protein/metabolism , Quinazolines/pharmacology , Carcinoma, Squamous Cell/immunology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cell Survival/genetics , Chemotherapy, Adjuvant , Drug Synergism , Gefitinib , Gene Expression Regulation, Neoplastic/drug effects , Humans , Imidazoles/pharmacology , Lung Neoplasms/immunology , MAP Kinase Kinase 3/metabolism , MAP Kinase Kinase 6/genetics , MAP Kinase Kinase 6/metabolism , MutS Homolog 2 Protein/genetics , Mutation/genetics , Pyridines/pharmacology , RNA, Small Interfering/genetics , Signal Transduction/drug effects , Transgenes/genetics , p38 Mitogen-Activated Protein Kinases/metabolism
7.
Naunyn Schmiedebergs Arch Pharmacol ; 386(12): 1047-59, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23912706

ABSTRACT

The multitargeted antifolate pemetrexed has demonstrated certain clinical activities against nonsmall cell lung cancer (NSCLC). Resveratrol (3,5,4-trihydroxy-trans-stilbene) is a polyphenol found in grapes and other plants and has great potential as a preventative and therapeutic agent due to its anticarcinogenic activity. The efficacy of adding resveratrol to pemetrexed to prolong the survival of patients with NSCLC still remains unclear. The excision repair cross-complementation 1 (ERCC1) is a DNA repair gene coding 5' endonuclease in nucleotide excision repair and is overexpressed in chemo- or radioresistant carcinomas. In this study, resveratrol (10-50 µM) inhibited cell survival in two NSCLC cells, H520 and H1975. Treatment with resveratrol increased ERCC1 messenger RNA and protein levels in a MKK3/6-p38 MAPK signal activation-dependent manner. Furthermore, blocking p38 MAPK activation by SB202190 or knocking down ERCC1 expression by transfection with small interfering RNA of ERCC1 enhanced the cytotoxicity of resveratrol. Combining resveratrol with pemetrexed resulted in a synergistic cytotoxic effect, accompanied with the reduction of phospho-p38 MAPK and ERCC1 protein levels, and a DNA repair capacity. Expression of constitutively active MKK6 (MKK6E) or HA-p38 MAPK vectors significantly rescued the decreased p38 MAPK activity, and restored ERCC1 protein levels and cell survival in resveratrol and pemetrexed cotreated NSCLC cells. In this study, for the first time, we have demonstrated the synergistic effect of combined treatment with resveratrol and pemetrexed in human NSCLC cells through downregulation of the MKK3/6-p38 MAPK-ERCC1 signal, suggesting a potential benefit of combining resveratrol and pemetrexed to treat lung cancer in the future.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Carcinoma, Non-Small-Cell Lung/enzymology , DNA-Binding Proteins/metabolism , Endonucleases/metabolism , Glutamates/pharmacology , Guanine/analogs & derivatives , Lung Neoplasms/enzymology , Stilbenes/pharmacology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Survival/drug effects , DNA Repair/drug effects , Dose-Response Relationship, Drug , Down-Regulation , Enzyme Activation , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , Guanine/pharmacology , Humans , Lung Neoplasms/genetics , Lung Neoplasms/pathology , MAP Kinase Kinase 3/metabolism , MAP Kinase Kinase 6/metabolism , Pemetrexed , Protein Kinase Inhibitors/pharmacology , RNA Interference , RNA, Messenger/metabolism , Resveratrol , Signal Transduction/drug effects , Time Factors , Transfection , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
8.
Basic Clin Pharmacol Toxicol ; 113(1): 56-65, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23362830

ABSTRACT

Metformin is an antidiabetic drug recently shown to inhibit cancer cell proliferation and growth, although the involved molecular mechanisms have not been elucidated. In many cancer cells, high expression of thymidine phosphorylase (TP) and Excision repair cross-complementation 1 (ERCC1) is associated with poor prognosis. We used A549 and H1975 human non-small cell lung cancer (NSCLC) cell lines to investigate the role of TP and ERCC1 expression in metformin-induced cytotoxicity. Metformin treatment decreased cellular TP and ERCC1 protein and mRNA levels by down-regulating phosphorylated MEK1/2-ERK1/2 protein levels in a dose- and time-dependent manner. The enforced expression of the constitutively active MEK1 (MEK1-CA) vectors significantly restored cellular TP and ERCC1 protein levels and cell viability. Specific inhibition of TP and ERCC1 expression by siRNA enhanced the metformin-induced cytotoxicity and growth inhibition. Arachidin-1, an antioxidant stilbenoid, further decreased TP and ERCC1 expression and augmented metformin's cytotoxic effect, which was abrogated in lung cancer cells transfected with MEK1/2-CA expression vector. In conclusion, metformin induces cytotoxicity by down-regulating TP and ERCC1 expression in NSCLC cells.


Subject(s)
DNA-Binding Proteins/biosynthesis , Endonucleases/biosynthesis , Hypoglycemic Agents/pharmacology , Metformin/pharmacology , Thymidine Phosphorylase/biosynthesis , Cell Line, Tumor , Dose-Response Relationship, Drug , Humans , MAP Kinase Kinase 1/biosynthesis , MAP Kinase Signaling System/drug effects , RNA, Messenger , RNA, Small Interfering , Time Factors
9.
Biochem Pharmacol ; 85(4): 583-94, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23228696

ABSTRACT

Metformin, an extensively used and well-tolerated drug for treating individuals with type 2 diabetes, has recently gained significant attention as an anticancer drug. On the other hand, paclitaxel (Taxol) is a new antineoplastic drug that has shown promise in the treatment of non-small cell lung cancer (NSCLC). High expression levels of excision repair cross-complementary 1 (ERCC1) in cancers have been positively associated with the DNA repair capacity and a poor prognosis in NSCLC patients treated with platinum-containing chemotherapy. In this current study, paclitaxel was found to increase phosphorylation of mitogen-activated protein kinase (MAPK) kinase 3/6 (MKK3/6)-p38 MAPK as well as protein and mRNA levels of ERCC1 in H1650 and H1703 cells. Moreover, paclitaxel-induced ERCC1 protein and mRNA levels significantly decreased via the downregulation of p38 activity by either a p38 MAPK inhibitor SB202190 or p38 knockdown with specific small interfering RNA (siRNA). Specific inhibition of ERCC1 with siRNA was found to enhance the paclitaxel-induced cytotoxic effect and growth inhibition. Furthermore, metformin was able to not only decrease the paclitaxel-induced p38 MAPK-mediated ERCC1 expression, but also augment the cytotoxic effect induced by paclitaxel. Finally, expression of constitutive activate MKK6 or HA-p38 MAPK vectors in lung cancer cells was able to abrogate ERCC1 downregulation by metformin and paclitaxel as well as cell viability and DNA repair capacity. Overall, our results suggest that inhibition of the p38 MAPK signaling by metformin coupled with paclitaxel therapy in human NSCLC cells may be a clinically useful combination, which however will require further validation.


Subject(s)
DNA Repair/physiology , DNA-Binding Proteins/metabolism , Endonucleases/metabolism , Metformin/pharmacology , Paclitaxel/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism , Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung , Cell Line, Tumor , Cell Survival/drug effects , DNA-Binding Proteins/genetics , Dose-Response Relationship, Drug , Down-Regulation/drug effects , Endonucleases/genetics , Humans , Hypoglycemic Agents/pharmacology , Lung Neoplasms , Metformin/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Up-Regulation/drug effects
10.
Regul Toxicol Pharmacol ; 64(3): 415-24, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23069143

ABSTRACT

Heat shock protein 90 (HSP90) is an exciting new target in cancer therapy. Repair protein Rad51 is involved in protecting non-small cell lung cancer (NSCLC) cell lines against chemotherapeutic agent-induced cytotoxicity. This study investigated the role of Rad51 expression in HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG)-induced cytotoxicity in two NSCLC cell lines, A549 and H1975. The 17-AAG treatment decreased cellular Rad51 protein and mRNA levels and phosphorylated MKK1/2-ERK1/2 protein levels, and disrupted the HSP90 and Rad51 interaction. This triggered Rad51 protein degradation through the 26S proteasome pathway. The 17-AAG treatment also decreased the NSCLC cells' DNA repair capacity, which was restored by the forced expression of the Flag-Rad51 vector. Specific inhibition of Rad51 expression by siRNA further enhanced 17-AAG-induced cytotoxicity. In contrast, enhanced ERK1/2 activation by the constitutively active MKK1/2 (MKK1/2-CA) vector significantly restored the 17-AAG-reduced Rad51 protein levels and cell viability. Arachidin-1, an antioxidant stilbenoid, further decreased Rad51 expression and augmented the cytotoxic effect and growth inhibition of 17-AAG. The 17-AAG and arachidin-1-induced synergistic cytotoxic effects and decreased DNA repair capacity were abrogated in lung cancer cells with MKK1/2-CA or Flag-Rad51 expression vector transfection. In conclusion, HSP90 inhibition induces cytotoxicity by down-regulating Rad51 expression and DNA repair capacity in NSCLC cells.


Subject(s)
Benzoquinones/pharmacology , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/pharmacology , Lung Neoplasms/drug therapy , Rad51 Recombinase/genetics , Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Survival/drug effects , DNA Repair/drug effects , Down-Regulation/drug effects , Drug Synergism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lung Neoplasms/pathology , RNA, Messenger/metabolism , RNA, Small Interfering/administration & dosage , Stilbenes/pharmacology
11.
Biochem Pharmacol ; 84(1): 126-36, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22480737

ABSTRACT

Elevated thymidine phosphorylase (TP) levels, a key enzyme in the pyrimidine nucleoside salvage pathway, are associated with an aggressive disease phenotype and poor prognoses. In this study, we examined the role of TP expression in relation to the HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG)-induced cytotoxicity in two non-small-cell lung cancer (NSCLC) cell lines, A549 and H1650. Treatment with 17-AAG (0.1-1 µM) resulted in a decrease in cellular TP protein and mRNA levels, which was accompanied by a downregulation of phosphorylated MKK1/2-ERK1/2 and AKT protein levels. The 17-AAG treatment disrupted the interaction between HSP90 and TP and triggered TP protein degradation through the ubiquitin-26S proteasome pathway. Specific inhibition of TP expression by siRNA further enhanced the cell death and growth inhibition that had been induced by 17-AAG. An enhancement of ERK1/2 or AKT activation by transfecting the cancer cells with constitutively active MKK1/2 or AKT expression vectors significantly restored the 17-AAG-reduced TP protein levels as well as cell viability. In contrast, a combination of U0126 (MKK1/2 inhibitors) or LY294002 (PI3K inhibitor) further decreased the TP expression and cell viability induced by 17-AAG. Moreover, 17-AAG enhanced the cisplatin-induced cytotoxic effect through downregulation of the cisplatin-induced TP expression and ERK1/2 and AKT activation. Taken together, our results suggest that the down-modulation of TP protein induced by 17-AAG represents a key factor in enhancing the cytotoxic effects of cisplatin in NSCLC cells.


Subject(s)
Antineoplastic Agents/pharmacology , Benzoquinones/pharmacokinetics , Cisplatin/pharmacology , Enzyme Inhibitors/pharmacology , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/pharmacokinetics , Thymidine Phosphorylase/antagonists & inhibitors , Blotting, Western , Carcinoma, Non-Small-Cell Lung/enzymology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Down-Regulation , Drug Synergism , Humans , Immunoprecipitation , Lung Neoplasms/enzymology , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Thymidine Phosphorylase/biosynthesis
12.
Mol Cancer Ther ; 11(3): 561-71, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22053010

ABSTRACT

Etoposide (VP-16), a topoisomerase II inhibitor, is an effective anticancer drug currently used for the treatment of a wide range of cancers. Excision repair cross-complementary 1 (ERCC1) is a key protein involved in the process of nucleotide excision repair. High level of ERCC1 expression in cancers is associated with resistance to DNA damage-based chemotherapy. In this study, the effects of p38 mitogen-activated protein kinase (MAPK) signal on the ERCC1 expression induced by etoposide in non-small cell lung cancer (NSCLC) cell lines was investigated. Etoposide increased phosphorylated MAPK kinase 3/6 (MKK3/6)-p38 MAPK and ERCC1 protein and mRNA levels in A549 and H1975 cells. Moreover, SB202190, a p38 inhibitor, or knockdown of p38 expression by specific short interfering RNA (siRNA) significantly decreased the etoposide-induced ERCC1 protein levels and DNA repair capacity in etoposide-exposed NSCLC cells. Enhancement of p38 activation by constitutively active MKK6 (MKK6E) increased ERCC1 protein levels. Specific inhibition of ERCC1 by siRNA significantly enhanced the etoposide-induced cytotoxicity and hypoxanthine guanine phosphoribosyltransferase (hprt) gene mutation rate. Moreover, the Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) could decrease the etoposide-induced p38 MAPK-mediated ERCC1 expression and augment the cytotoxic effect and growth inhibition by etopsoside. 17-AAG and etoposide-induced synergistic cytotoxic effect and DNA repair capacity decrease could be abrogated in lung cancer cells with MKK6E or HA-p38 MAPK expression vector transfection. Our results suggest that in human NSCLC cells, ERCC1 is induced by etoposide through the p38 MAPK pathway, and this phenomenon is required for NSCLC survival and resistant DNA damage.


Subject(s)
DNA Repair , DNA-Binding Proteins/metabolism , Endonucleases/metabolism , Etoposide/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism , Antineoplastic Agents, Phytogenic/pharmacology , Benzoquinones/pharmacology , Blotting, Western , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Survival/drug effects , DNA-Binding Proteins/genetics , Dose-Response Relationship, Drug , Drug Synergism , Endonucleases/genetics , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Humans , Imidazoles/pharmacology , Lactams, Macrocyclic/pharmacology , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Phosphorylation/drug effects , Pyridines/pharmacology , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/genetics
13.
IEEE Trans Inf Technol Biomed ; 14(2): 292-300, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20007057

ABSTRACT

One of the major goals of healthcare systems is to automatically monitor patients of special needs and alarm the caregivers for providing assistant. In this paper, an efficient single-camera multidirectional wheelchair detector based on a cascaded decision tree (CDT) is proposed to detect a wheelchair and its moving direction simultaneously from video frames for a healthcare system. Our approach combines a decision tree structure and boosted-cascade classifiers to construct a new CDT that can perform early confidence decisions in a hierarchical manner to rapidly reject nonwheelchairs and decide the moving directions. We also impose the tracking history to guide detection routes in the CDT to further reduce detection time and increase detection accuracy. The experiments show over 92% detection rate under cluttered scenes.


Subject(s)
Decision Trees , Image Processing, Computer-Assisted/methods , Pattern Recognition, Automated/methods , Video Recording , Wheelchairs , Algorithms , Humans , Motion , Population Surveillance/methods
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