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1.
J Ultrasound Med ; 43(2): 385-395, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37994205

ABSTRACT

The intermittent injection of teriparatide, a recombinant fragment of human parathyroid hormone (PTH 1-34), activates anabolic activity on bone turnover. However, the PTH administration period is limited to 2 years. Thus, sequential therapy after discontinuation of PTH is required. Low-intensity pulsed ultrasound (LIPUS) has been widely used for bone fracture healing. In this study, we examined the effects of LIPUS on bone mass after PTH withdrawal in ovariectomized (OVX) model mice. The LIPUS-non-irradiated femoral trabecular bone mineral density (BMD) in the treated after PTH withdrawal was significantly decreased. Meanwhile, the femoral BMD in the OVX + PTH-LIPUS group was remarkably higher than that of the OVX group. Additionally, mRNA expression of Runx2, Osterix, Col1a1, and ALP increased significantly following LIPUS irradiation after PTH withdrawal. These results suggest that LIPUS protected against femoral trabecular BMD loss and up-regulated the osteogenic factors following PTH withdrawal in OVX mice.


Subject(s)
Bone Density , Parathyroid Hormone , Humans , Mice , Animals , Female , Parathyroid Hormone/pharmacology , Osteogenesis , Ultrasonic Waves , Ovariectomy
2.
BMC Cancer ; 21(1): 1111, 2021 Oct 16.
Article in English | MEDLINE | ID: mdl-34656107

ABSTRACT

BACKGROUND: Among patients with colorectal cancer (CRC) treated with oxaliplatin (L-OHP)-based chemotherapy, delayed chemotherapy-induced nausea and vomiting (CINV) have not been well controlled. METHODS: We pooled data from two prospective observational studies in Japan and one phase III clinical trial to assess whether delayed CINV could be controlled with a combination of three antiemetics adding a neurokinin-1 receptor antagonist and identified individual risk factors, using an inverse probability treatment-weighted analysis. RESULTS: A total of 661 patients were evaluable in this study (median age: 64 years; 391 male, and 270 female). 3 antiemetics controlled delayed nausea (33.18% vs. 42.25%; p = 0.0510) and vomiting (4.15% vs. 16.08%; p < 0.0001) better than with 2 antiemetics. Female and 2 antiemetics were risk factors for both delayed nausea (female-odds ratio [OR]: 1.918; 95% confidence interval [CI]: 1.292-2.848; p = 0.0012; 2 antiemetics-OR: 1.485; 95% CI: 1.000-2.204; p = 0.0498) and delayed vomiting (female-OR: 2.735; 95% CI: 1.410-5.304; p = 0.0029; 2 antiemetics-OR: 4.551; 95% CI: 2.116-9.785; p = 0.0001). CONCLUSIONS: Identifying individual risk factors can facilitate personalized treatments for delayed CINV. We recommend a 3-antiemetic combination prophylaxis for CRC patients treated with L-OHP-based chemotherapy, especially for female patients.


Subject(s)
Antiemetics/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Colorectal Neoplasms/drug therapy , Nausea/drug therapy , Vomiting/drug therapy , Aged , Capecitabine/adverse effects , Clinical Trials, Phase III as Topic , Drug Therapy, Combination , Female , Fluorouracil/adverse effects , Humans , Japan , Leucovorin/adverse effects , Male , Middle Aged , Nausea/chemically induced , Neurokinin-1 Receptor Antagonists/therapeutic use , Observational Studies as Topic , Organoplatinum Compounds/adverse effects , Oxaloacetates/adverse effects , Randomized Controlled Trials as Topic , Risk Factors , Sex Factors , Vomiting/chemically induced
3.
Support Care Cancer ; 29(9): 5029-5035, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33590260

ABSTRACT

PURPOSE: Dexamethasone (DEX)-sparing strategies (one-day DEX) with palonosetron as doublet antiemetic prophylaxis have previously been studied. However, DEX-sparing regimens with 5-hydroxytryptamine-3 receptor antagonist (5-HT3RA) and aprepitant (APR), as triplet antiemetic prophylaxis, have not been evaluated. This study aimed to evaluate the efficacy of a combination of 5-HT3RA, APR, and DEX on day 1 of carboplatin (CBDCA)-based chemotherapy in patients with lung cancer. METHODS: Data were pooled from a nationwide, multicenter, prospective observational study using propensity score-matched analysis to compare the incidence of chemotherapy-induced nausea and vomiting (CINV) between one- and multiple-day DEX regimens in combination with 5-HT3RA plus APR. RESULTS: Incidence of delayed nausea was significantly higher in the one-day than in the multiple-day DEX group. Incidence of nausea was also significantly higher in the one-day than in the multiple-day DEX group on days 3-5. Kaplan-Meier curves for nausea showed a significant difference between the two groups; however, there was no significant difference in the occurrence of vomiting or the Kaplan-Meier curves of time to vomiting. CONCLUSION: To the best of our knowledge, this study is the first to evaluate the efficacy of a DEX-sparing regimen by comparing one- and multiple-day DEX combined with 5-HT3RA and APR concerning CINV incidence in lung cancer patients receiving CBDCA-based chemotherapy. Antiemetic regimens of one-day DEX result in poor control of delayed nausea; therefore, we recommend the application of the DEX-sparing strategy only after careful patient selection while considering the development of nausea.


Subject(s)
Lung Neoplasms , Antiemetics/therapeutic use , Antineoplastic Agents/adverse effects , Carboplatin/adverse effects , Dexamethasone/therapeutic use , Humans , Lung Neoplasms/drug therapy , Nausea/chemically induced , Nausea/epidemiology , Nausea/prevention & control , Propensity Score , Vomiting/chemically induced , Vomiting/drug therapy
4.
J Thorac Dis ; 16(1): 430-438, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38410572

ABSTRACT

Background: Numerous meta-analyses have examined immunotherapy-induced adverse events (AEs) in non-small cell lung cancer (NSCLC). However, there is limited research comparing AEs from combination chemoimmunotherapy versus chemotherapy alone in the first-line NSCLC treatment, particularly regarding specific toxic symptoms and hematological toxicities associated with the addition of immune checkpoint inhibitors (ICIs). Methods: We conducted a meta-analysis of randomized clinical trials (RCTs) comparing ICIs + non-ICIs versus non-ICIs alone as first-line therapy in NSCLC, sourced from PubMed and Scopus databases. Our objective was to assess treatment-related AEs in both regimens, focusing on identifying the more prevalent toxic symptoms and hematological toxicities with ICI treatment. We calculated the relative risks (RRs) and 95% confidence intervals (CIs), and estimated the pooled RRs and 95% CIs using common- or random-effects models. Results: Our analysis included 10 trials with 6,008 patients. Combination chemoimmunotherapy significantly increased the risk of grade 3 or higher treatment-related AEs, treatment discontinuation, and deaths due to treatment-related AEs. Moreover, patients receiving combination chemoimmunotherapy had a significantly higher risk of certain toxic symptoms (all-grade: vomiting, diarrhea, and constipation; high-grade: fatigue and diarrhea) and pneumonitis (both all-grade and high-grade). Conclusions: These findings offer crucial insights into the toxicity profile of combination chemoimmunotherapy, serving as a valuable resource for clinicians managing lung cancer care.

5.
Cancer Med ; 13(7): e7107, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38591098

ABSTRACT

BACKGROUND: Long-term anti-EGFR antibody treatment increases the risk of severe dermatologic toxicities. This single-arm, phase II trial aimed to investigate the strategy of switching from cetuximab to bevacizumab in combination with FOLFIRI based on early tumor shrinkage (ETS) in patients with RAS wild-type metastatic colorectal cancer (mCRC). METHODS: Radiologic assessment was performed to evaluate ETS, defined as ≥20% reduction in the sum of the largest diameters of target lesions 8 weeks after the introduction of FOLFIRI plus cetuximab. ETS-negative patients switched to FOLFIRI plus bevacizumab, whereas ETS-positive patients continued FOLFIRI plus cetuximab for eight more weeks, with a switch to FOLFIRI plus bevacizumab thereafter. The primary endpoint was progression-free survival. RESULTS: This trial was prematurely terminated due to poor accrual after a total enrollment of 30 patients. In 29 eligible patients, 7 were ETS-negative and 22 were ETS-positive. Two ETS-negative patients and 17 ETS-positive patients switched to FOLFIRI plus bevacizumab 8 weeks and 16 weeks after initial FOLFIRI plus cetuximab, respectively. Median progression-free and overall survival durations were 13.4 and 34.7 months, respectively. Six (20%) patients experienced grade ≥3 paronychia, which improved to grade ≤2 by 18 weeks. Grade ≥3 acneiform rash, dry skin, and pruritus were not observed in any patients. CONCLUSIONS: Our novel treatment strategy delivered acceptable survival outcomes and reduced severe dermatologic toxicities.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Rectal Neoplasms , Humans , Bevacizumab/adverse effects , Cetuximab/adverse effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Camptothecin/adverse effects , Fluorouracil/adverse effects , Colonic Neoplasms/etiology , Rectal Neoplasms/etiology , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Leucovorin/adverse effects
6.
Thorac Cancer ; 14(17): 1597-1605, 2023 06.
Article in English | MEDLINE | ID: mdl-37073452

ABSTRACT

BACKGROUND: Previous trials suggest that older adults with non-small cell lung cancer (NSCLC) derive benefit from platinum doublet combination therapy, but its superiority is controversial. Although geriatric assessment variables are used to assess the individual risk of severe toxicity and clinical outcomes in older patients, the standard first-line treatment is still debated. Therefore, we aimed to identify the risk factors for clinical outcomes in older patients with NSCLC. METHODS: Patients aged ≥75 years with advanced NSCLC treated at any of 24 National Hospital Organization institutions completed a pre-first-line chemotherapy assessment, including patient characteristics, treatment variables, laboratory test values, and geriatric assessment variables. We evaluated whether these variables were the risk factors for progression-free survival (PFS) and overall survival (OS). RESULTS: A total of 148 patients with advanced NSCLC were treated with combination therapy (n = 90) or monotherapy (n = 58). Median PFS was 5.3 months and OS was 13.6 months. We identified that hypoalbuminemia (hazard ratio [HR] 2.570, 95% confidence interval [CI]: 1.117-5.913, p = 0.0264) was a risk factor for PFS and monotherapy (HR 1.590, 95% CI: 1.070-2.361, p = 0.0217), lactate dehydrogenase (HR 3.682, 95% CI: 1.013-13.39, p = 0.0478), and high C-reactive protein (HR 2.038, 95% CI: 1.141-3.642, p = 0.0161) were risk factors for OS. The median OS was significantly longer in patients treated with combination therapy than in those who received monotherapy (16.5 months vs. 10.3 months; HR 0.684, 95% CI: 0.470-0.995, p = 0.0453). DISCUSSION: Platinum doublet combination therapy may be beneficial in older patients with NSCLC. Identification of risk factors will assist in the development of a personalized treatment strategy.


Subject(s)
Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Aged , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Platinum/therapeutic use , Antineoplastic Agents/therapeutic use , Japan , Prospective Studies , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Hospitals
7.
Biochem Biophys Res Commun ; 418(1): 62-6, 2012 Feb 03.
Article in English | MEDLINE | ID: mdl-22240020

ABSTRACT

To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A)(+) RNA transport] 1 to 11, which accumulate poly(A)(+) RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5-1 mutant shows dots- or a ring-like accumulation of poly(A)(+) RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5(+) gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5-1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5-1 mutation. In addition, we found that the ptr5-1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5-1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.


Subject(s)
Cell Nucleus/metabolism , Nuclear Pore Complex Proteins/metabolism , RNA, Messenger/metabolism , Schizosaccharomyces pombe Proteins/metabolism , Schizosaccharomyces/metabolism , Active Transport, Cell Nucleus , Alternative Splicing , Genes, Fungal , Nuclear Matrix-Associated Proteins/genetics , Nuclear Matrix-Associated Proteins/metabolism , Nuclear Pore Complex Proteins/genetics , Nucleocytoplasmic Transport Proteins/genetics , Nucleocytoplasmic Transport Proteins/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Schizosaccharomyces/genetics , Schizosaccharomyces pombe Proteins/genetics , Suppression, Genetic
8.
Eur J Med Res ; 27(1): 157, 2022 Aug 23.
Article in English | MEDLINE | ID: mdl-35999618

ABSTRACT

INTRODUCTION: Recently, several meta-analyses have investigated the association between sex and the efficacy of immune checkpoint inhibitors (ICIs) in non-small-cell lung cancer (NSCLC). However, this issue remains controversial, because the results have been inconsistent. Moreover, the effect of sex on outcomes in patients with NSCLC receiving combination chemoimmunotherapy as a first-line therapy is poorly understood. The aim of this study was to examine the association between sex and outcomes in patients with NSCLC receiving combination chemoimmunotherapy as a first-line therapy. METHODS: We searched PubMed and Scopus from database inception to Feb 18, 2022 and performed a systematic review and meta-analysis of randomized and controlled clinical trials investigating ICI+non-ICI vs non-ICI as a first-line therapy in NSCLC. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS) in male and female patients were calculated using common and random-effects models. RESULTS: We analyzed 5,830 patients, comprising 4,137 (71.0%) males and 1,693 (29.0%) females, from nine randomized clinical trials. The pooled HR (95%CI) for OS comparing ICI+non-ICI vs non-ICI was 0.80 (0.72-0.87) for males and 0.69 (0.54-0.89) for females. The pooled HR (95%CI) for PFS comparing ICI+non-ICI vs non-ICI was 0.60 (0.55-0.66) for males and 0.56 (0.44-0.70) for females. CONCLUSIONS: In patients with NSCLC receiving combination chemoimmunotherapy as a first-line therapy, a greater improvement in OS and PFS was observed in female patients than in male patients.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Carcinoma, Non-Small-Cell Lung/drug therapy , Female , Humans , Immunotherapy , Lung Neoplasms/drug therapy , Male , Randomized Controlled Trials as Topic
9.
Cancer Manag Res ; 14: 2673-2680, 2022.
Article in English | MEDLINE | ID: mdl-36110158

ABSTRACT

Purpose: The incidence of delayed chemotherapy-induced nausea and vomiting (CINV) in patients with non-small cell lung cancer (NSCLC) receiving carboplatin (CBDCA)-based chemotherapy (CBDCA + pemetrexed or paclitaxel) has not been clearly described. Therefore, we attempted to evaluate whether delayed CINV could be controlled using a combination of three antiemetics and identify individual risk factors. Methods: We pooled data from two prospective observational studies, namely a nationwide survey of CINV and a prospective, observational study in Japan, to assess whether delayed CINV could be controlled using a combination of three antiemetics and identified individual risk factors via inverse probability treatment-weighted analysis. Results: In total, 240 patients were evaluable in this study (median age, 66 years; male, 173; female, 67). The three-antiemetic regimen controlled delayed nausea (31.6% vs 47.3%) and vomiting (5.1% vs 23.1%) better than two antiemetics. Younger age (<70 years; odds ratio [OR] = 2.233), motion sickness (OR = 3.472), drinking habits (OR = 1.972), receipt of the CBDCA + pemetrexed regimen (OR = 2.041), and the use of two antiemetics (OR = 1.926) were risk factors for delayed nausea. Female sex (OR = 3.372), drinking habits (OR = 2.272), receipt of the CBDCA+ pemetrexed regimen (OR = 2.314), and the use of two antiemetics (OR = 6.830) were risk factors for delayed vomiting. Conclusion: Female sex, younger age, and receipt of the CBDCA + pemetrexed regimen increased the risk of CINV. Therefore, we recommend additional supportive antiemetics treatment for these patients.

10.
Hypertension ; 76(6): 1906-1914, 2020 12.
Article in English | MEDLINE | ID: mdl-33131306

ABSTRACT

The estimated morbidity rate of chronic kidney disease is 8% to 16% worldwide, and many patients with chronic kidney disease eventually develop renal failure. Thus, the development of new therapeutic strategies for preventing renal failure is crucial. In this study, we assessed the effects of daily low-intensity pulsed ultrasound (LIPUS) therapy on experimental hypertensive nephropathy and diabetic nephropathy. Unilateral nephrectomy and subcutaneous infusion of angiotensin II via osmotic mini-pumps were used to induce hypertensive nephropathy in mice. Immunohistochemistry revealed that daily LIPUS treatment ameliorated renal fibrosis and infiltration of inflammatory cells induced by angiotensin II. A similar therapeutic effect was also observed in mice with angiotensin II-induced hypertensive nephropathy in which splenectomy was performed. In addition, LIPUS treatment significantly decreased systolic blood pressure after 21 days. Subsequently, db/db mice with unilateral nephrectomy developed proteinuria; daily LIPUS treatment significantly reduced proteinuria after 42 days. In addition, immunohistochemistry revealed that renal fibrosis was significantly ameliorated by LIPUS treatment. Finally, LIPUS stimulation suppressed TGF-ß1 (transforming growth factor-ß1)-induced phosphorylation of Smad2 and Smad3 in HK-2 (human proximal tubular cell line) cells. LIPUS treatment may be a useful therapy for preventing the progression of renal fibrosis in patients with chronic kidney disease.


Subject(s)
Diabetic Nephropathies/therapy , Hypertension, Renal/therapy , Kidney/pathology , Nephritis/therapy , Ultrasonic Therapy/methods , Ultrasonic Waves , Actins/genetics , Actins/metabolism , Animals , Cell Line , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/physiopathology , Disease Models, Animal , Fibrosis/therapy , Humans , Hypertension, Renal/metabolism , Hypertension, Renal/physiopathology , Inflammation/metabolism , Inflammation/therapy , Male , Mice, Inbred C57BL , Mice, Knockout , Myocytes, Smooth Muscle/metabolism , Nephritis/metabolism , Nephritis/physiopathology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
11.
Genes Cells ; 13(8): 817-26, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18651850

ABSTRACT

Mediator is an essential transcriptional cofactor of RNA polymerase II (Pol II) in eukaryotes. This cofactor is a large complex containing up to 30 subunits and consisting of four modules: head, middle, tail, and CDK/Cyclin. Generally, Mediator connects transcriptional regulators, cofactors, chromatin regulators, and chromatin remodellers, with the pre-initiation complex to provide a platform for the assembly of these factors. Many previous studies have revealed that CDK8, a subunit of the CDK/Cyclin module, is one of the key subunits mediating the pivotal roles of Mediator in transcriptional regulation. In addition to CDK8, CDK11 is conserved among vertebrates as a Mediator subunit and closely resembles CDK8. While the role of CDK8 has been studied extensively, little is known of the role of CDK11 in Mediator. We purified human CDK11 (hCDK11)-containing protein complexes from an epitope-tagged hCDK11-expressing HeLa cell line and found that hCDK11 could independently form Mediator complexes devoid of human CDK8 (hCDK8). To investigate the in vivo transcriptional activity of the complex, we employed a luciferase assay. Although hCDK11 has nearly 80% amino acid sequence identity to hCDK8, siRNA-knockdown study revealed that hCDK8 and hCDK11 possess opposing functions in viral activator VP16-dependent transcriptional regulation.


Subject(s)
Cyclin-Dependent Kinases/metabolism , Herpes Simplex Virus Protein Vmw65/genetics , Amino Acid Sequence , Animals , Cyclin-Dependent Kinase 8 , Cyclin-Dependent Kinases/chemistry , HeLa Cells , Humans , Molecular Sequence Data
12.
PLoS One ; 6(4): e19442, 2011 Apr 29.
Article in English | MEDLINE | ID: mdl-21559379

ABSTRACT

BACKGROUND: The control of gene expression is essential for growth and responses to environmental changes in various organisms. It is known that some meiosis-specific genes are silenced during mitosis and expressed upon nitrogen starvation in Schizosaccharomyces pombe. When the factors responsible for this regulation were studied, a hip3 mutant was isolated via discovery of a defect in the transcriptional repression of meiosis-specific genes. Hip3 is a subunit of the HIRA (histone regulatory complex A) complex, which consists of four subunits (Hip1, Hip3, Hip4 and Slm9) and acts as a histone chaperone that is independent of DNA replication. METHODOLOGY/PRINCIPAL FINDINGS: In a search for mutants, the meiosis-specific gene SPCC663.14c(+) was identified by screening for genes that are silenced during mitosis and induced upon nitrogen starvation. A reporter plasmid that expresses the ura4(+) gene driven by the SPCC663.14c(+) promoter was constructed. Screening for suppressor mutants was then carried out in nitrogen-rich medium without uracil. A mutant with a mutation in the hip3(+) gene was isolated and named hip3-1. This mutation alleviated the transcriptional repression of the ura4(+) gene on the reporter plasmid and of the endogenous SPCC663.14c(+) gene in the presence of nitrogen. A ChIP assay revealed that RNA polymerase II (Pol II) and TFIIE were enriched at the SPCC663.14c(+) locus, whereas the levels of histone H3 were decreased in hip3-1 cells. Intriguingly, histone H3 was heavily modified at the SPCC663.14c(+) locus in hip3-1 cells; these modifications included tri-methylation and acetylation of H3 lysine 9 (H3K9), mono-methylation of H3 arginine 2 (H3R2), and tri-methylation of H3 lysine 4 (H3K4). In addition, the tri-methylation of H3K9 and H3K4 were strongly elevated in hip3-1 mutants. CONCLUSIONS: Taken together, these results indicate that Hip3 plays important roles in the control of histone modifications at meiosis-specific gene loci and induces their transcriptional repression.


Subject(s)
Gene Expression Regulation, Fungal , Gene Silencing , Histones/chemistry , Meiosis , Molecular Chaperones/genetics , Schizosaccharomyces pombe Proteins/genetics , Schizosaccharomyces/genetics , Schizosaccharomyces/metabolism , Chromatin/metabolism , Genes, Fungal , Histones/metabolism , Models, Genetic , Molecular Chaperones/physiology , Mutation , Phosphorylation , Plasmids/metabolism , Schizosaccharomyces pombe Proteins/physiology , Temperature , Transcription, Genetic
13.
Genes Cells ; 12(1): 35-47, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17212653

ABSTRACT

To identify novel factors involved in nuclear mRNA export in Schizosaccharomyces pombe, we isolated and characterized the ptr8(+) gene, mutation of which causes nuclear accumulation of poly (A)(+) RNA. The ptr8(+) gene encodes an S. pombe homologue of human XPB, a component of TFIIH involved in nucleotide excision repair (NER) and transcription. A temperature-sensitive mutant of ptr8(+) (ptr8-1) was highly sensitive to UV irradiation, as are human XPB cells. Northern blot analysis demonstrated that the amount of total poly (A)(+) mRNAs does not decrease significantly at the nonpermissive temperature in ptr8-1 cells, whereas a pulse-labeling assay using (35)S-methionine showed that protein synthesis decreases rapidly after incubation of cells at the nonpermissive temperature, suggesting that ptr8-1 cells have a defect in nuclear mRNA export. In Saccharomyces cerevisiae, a mutation in the SSL2 gene encoding a homologue of Ptr8p also causes a block of mRNA export at the nonpermissive temperature. In addition, expression of human XPB in ptr8-1 cells rescued the ts phenotype and the mRNA export defects, suggesting that human XPB may also play a role in mRNA export. Furthermore, we revealed a functional interaction between Ptr8p and Tho2p, a component of the TREX complex involved in mRNA export. These results suggest that XPB/Ptr8p plays roles not only in NER and transcription, but also plays a conserved role in mRNA export.


Subject(s)
Cell Nucleus/metabolism , RNA, Messenger/metabolism , Schizosaccharomyces pombe Proteins/physiology , Schizosaccharomyces/metabolism , Transcription Factor TFIIH/metabolism , Active Transport, Cell Nucleus , Amino Acid Sequence , Cell Nucleolus/metabolism , Cockayne Syndrome/metabolism , DNA Helicases/genetics , DNA Helicases/metabolism , DNA Repair , Humans , In Situ Hybridization, Fluorescence , Molecular Sequence Data , Mutation , Poly A/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Schizosaccharomyces pombe Proteins/genetics , Schizosaccharomyces pombe Proteins/metabolism , Sequence Alignment , Temperature , Transcription Factor TFIIH/genetics , Transcription Factor TFIIH/physiology
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