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2.
Int J Mol Sci ; 25(7)2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38612630

ABSTRACT

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death 1 ligand 1 (PD-L1) antibodies, are significantly changing treatment strategies for human malignant diseases, including oral cancer. Cancer cells usually escape from the immune system and acquire proliferative capacity and invasive/metastatic potential. We have focused on the two immune checkpoints, PD-1/PD-L1 and CD47/SIRPα, in the tumor microenvironment of oral squamous cell carcinoma (OSCC), performed a retrospective analysis of the expression of seven immune-related factors (PD-L1, PD-1, CD4, CD8, CD47, CD56 and CD11c), and examined their correlation with clinicopathological status. As a result, there were no significant findings relating to seven immune-related factors and several clinicopathological statuses. However, the immune checkpoint-related factors (PD-1, PD-L1, CD47) were highly expressed in non-keratinized epithelium-originated tumors when compared to those in keratinized epithelium-originated tumors. It is of interest that immunoediting via immune checkpoint-related factors was facilitated in non-keratinized sites. Several researchers reported that the keratinization of oral mucosal epithelia affected the immune response, but our present finding is the first study to show a difference in tumor immunity in the originating epithelium of OSCC, keratinized or non-keratinized. Tumor immunity, an immune escape status of OSCC, might be different in the originating epithelium, keratinized or non-keratinized.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Squamous Cell Carcinoma of Head and Neck , B7-H1 Antigen , CD47 Antigen , Programmed Cell Death 1 Receptor , Retrospective Studies , Epithelium , Tumor Microenvironment
3.
Clin Nutr ESPEN ; 60: 11-16, 2024 04.
Article in English | MEDLINE | ID: mdl-38479898

ABSTRACT

BACKGROUND & AIMS: This study aimed to investigate the association between trunk muscle mass and muscle quality, as evaluated by bioelectrical impedance analysis (BIA), and the ability to walk independently in patients with hip fractures. Cutoff values for quantitative and qualitative indicators of the trunk muscles were also calculated. METHODS: This study included 181 patients with hip fractures who were admitted to a convalescent rehabilitation ward. Trunk muscle mass and phase angle of the participants were evaluated on admission. The phase angle in this study was defined as the trunk muscle quality index (TMQI). Patients were classified into the independent (functional independence measure [FIM]-walk score ≥6; n = 101) and non-independent (FIM-walk score ≤5; n = 80) walking groups according to the FIM mobility scores at discharge. RESULTS: The independent group had a higher FIM gain than the non-independent group (37.0 ± 13.6 vs. 27.1 ± 13.5, p < 0.001). Logistic regression analysis showed that the trunk muscle mass index (TMI) and TMQI were associated with the ability to walk independently. Furthermore, cutoff values of TMI and TMQI for male and female to estimate the ability to walk independently were 6.5 kg/m2 and 5.7 kg/m2, and 4.5° and 3.4°, respectively. CONCLUSION: TMI and TMQI are related to the ability to walk independently in patients with hip fractures. These results suggest the importance of improving trunk muscle mass and muscle quality during rehabilitation of patients with hip fractures.


Subject(s)
Activities of Daily Living , Hip Fractures , Humans , Male , Female , Walking , Muscle, Skeletal , Hospitalization
4.
J Aging Phys Act ; 32(1): 1-7, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37295783

ABSTRACT

We investigated the association between the cross-sectional area (CSA) of the gluteus medius muscle (GMM) and activities of daily living in patients with hip fractures. This retrospective cohort study comprised 111 patients aged ≥65 years who underwent hip fracture rehabilitation. The CSA of the GMM was measured using computed tomography scans in the early stages of hospitalization. The group with decreased CSA of the GMM had a median GMI ≤17 cm2/m2 for male patients and ≤16 cm2/m2 for female patients. Patients in the group with decreased CSA of the GMM had lower functional independence measure gains than those in the control group. After adjusting for confounders, we found that decreased CSA of the GMM was significantly associated with lower functional independence measure gains (ß: -0.432, p < .001). In patients with hip fractures, decreased CSA of the GMM was associated with decreased activities of daily living.


Subject(s)
Activities of Daily Living , Hip Fractures , Humans , Male , Female , Aged , Retrospective Studies , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/physiology , Thigh
5.
Prog Rehabil Med ; 8: 20230036, 2023.
Article in English | MEDLINE | ID: mdl-37854311

ABSTRACT

Objectives: This study aimed to investigate the relationship between trunk muscle mass index (TMI), appendicular skeletal muscle mass index (ASMI), and walking independence in patients aged 65 years and older undergoing rehabilitation for hip fracture. Methods: This retrospective, observational study was conducted in a convalescent rehabilitation ward and included 314 patients (aged ≥65 years) with hip fracture. The patients were classified into the independence group [functional independence measure (FIM)-walk score ≥6] or the non-independence group (FIM-walk score ≤5) according to the mobility item score among the motor FIM items at the time of discharge. Age, sex, TMI, ASMI, and Mini Nutritional Assessment-Short Form (MNA-SF) data were also extracted. Between-group and multivariate analyses were performed to evaluate the factors associated with walking independence. Results: The independence group had higher TMI (males: 6.6±0.9 vs. 5.6±1.0 kg/m2, P <0.001; females: 6.1±0.8 vs. 5.7±1.0 kg/m2, P <0.001), ASMI (males: 6.7±1.1 vs. 5.9±1.3 kg/m2, P=0.004; females: 5.3±0.9 vs. 4.7±0.8 kg/m2, P <0.001), MMSE-J (21.5±4.9 vs. 16.4±4.5 points, P <0.001), and MNA-SF [median (interquartile range): 8 (6-9) vs. 7 (5-8) points, P <0.001] than the non-independence group. Multivariate analysis showed that TMI at admission was significantly associated with walking independence (odds ratio: 1.86, 95% confidence interval: 1.28-2.72, P <0.001). Conclusions: This study suggests that a higher TMI at admission was important for acquiring walking independence in patients with hip fracture and shows the importance of early evaluation of TMI during hospitalization of patients with hip fracture.

6.
Chem Commun (Camb) ; 59(72): 10801-10804, 2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37594189

ABSTRACT

A multi-component coordination compound, in which ruthenium antenna complexes are connected to a polyoxotungstate core is presented. This hybrid cluster effectively promotes the electrochemical conversion of CO2 to C1 feedstocks, the selectivity of which can be controlled by the acidity of the media.

7.
Nutrients ; 15(13)2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37447315

ABSTRACT

Many countries are facing the advent of super-aging societies, where sarcopenia and frailty will become pertinent problems. The prevalence of comorbidities is a major problem in countries with aged populations as elderly people suffer from various diseases, such as diabetes, heart failure, chronic kidney disease and dementia. All of these diseases are associated with sarcopenia and frailty, and they frequently cause falls, fractures, and a decline in activities of daily living. Fractures in the elderly people are associated with bone fragility, which is influenced by diabetes and chronic kidney disease. Nutritional support for chronic disease patients and sarcopenic individuals with adequate energy and protein intake, vitamin D supplementation, blood glucose level management for individuals with diabetes, obesity prevention, nutritional education for healthy individuals, and the enlightenment of society could be crucial to solve the health-related problems in super-aging societies.


Subject(s)
Diabetes Mellitus , Frailty , Renal Insufficiency, Chronic , Sarcopenia , Aged , Humans , Sarcopenia/epidemiology , Sarcopenia/prevention & control , Sarcopenia/complications , Frailty/epidemiology , Frailty/prevention & control , Frailty/complications , Frail Elderly , Activities of Daily Living , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/complications
8.
J Aging Phys Act ; 31(6): 965-971, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37343947

ABSTRACT

This study evaluated the relationship between the muscle mass of the gluteus medius (GM) and skeletal muscle mass index (SMI) measured in patients with hip fractures. In this study, 141 patients with hip fractures were divided into those with high or low SMI. The GM index (GMI) was calculated by dividing the GM by the square of the height in meters. The correlation between GMI and SMI was subsequently analyzed, and cutoff values for determining the loss of skeletal muscle mass were calculated using the receiver operating characteristic curve. GMI and SMI showed a positive correlation for both sexes (male: r = .890, female: r = .626, p < .001). The GMI cutoff values were 19.460 cm2/m2 for males and 17.850 cm2/m2 for females. Skeletal muscle mass evaluation of the GM could contribute to hip fracture recovery by improving mobility and facilitating the early diagnosis of loss of SMM.


Subject(s)
Hip Fractures , Muscle, Skeletal , Humans , Male , Female , Aged , Muscle, Skeletal/physiology , Thigh
9.
J Med Ultrason (2001) ; 50(2): 237-243, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36961646

ABSTRACT

PURPOSE: Anterior knee pain (AKP) may occur after anterior cruciate ligament (ACL) reconstruction. The present study investigated the relationship between the change in infrapatellar fat pad (IFP) thickness assessed using ultrasonography (US) and AKP on squatting in patients after ACL reconstruction. METHODS: Patients were enrolled 3 months after ACL reconstruction using the bone-tendon-bone (BTB) technique. Subjects were divided into the AKP group (numerical rating scale [NRS] score ≥ 1) and control group (NRS score < 1) using a NRS of pain on squatting, and intergroup comparisons were performed. On US evaluation, measurement angles of the knee joint were 0° and 30° in the supine position. The IFP between the femoral intercondylar notch and patellar tendon was measured on short-axis images. The changes in IFP thickness were calculated from values measured at different angles of the knee joint. RESULTS: Twenty-one patients (mean age 24.9 ± 9.3 years) were included in the present study: 12 in the AKP group (9 males, 3 females) and nine in the control group (5 males, 4 females). A significant difference in the change in IFP thickness at 3 months was observed between the AKP and control groups (0.67 ± 0.44 mm vs. 1.84 ± 0.34 mm, p < 0.001). There was a negative correlation between the change in IFP thickness and the NRS score (r = - 0.720, p < 0.001) in reconstructed knees. CONCLUSION: A smaller change in IFP thickness assessed using US after ACL reconstruction was identified as a factor contributing to AKP on squatting.


Subject(s)
Anterior Cruciate Ligament Injuries , Anterior Cruciate Ligament Reconstruction , Male , Female , Humans , Adolescent , Young Adult , Adult , Anterior Cruciate Ligament Injuries/surgery , Knee Joint/diagnostic imaging , Knee Joint/surgery , Anterior Cruciate Ligament Reconstruction/methods , Pain , Adipose Tissue/diagnostic imaging , Ultrasonography
10.
J Int Med Res ; 51(3): 3000605231161223, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36942446

ABSTRACT

The main symptom in primary syphilis is a small, painless, sore or ulcer called a chancre on the penis, vagina, or around the anus, although chancres can sometimes appear in the mouth or on the lips, fingers, or buttocks. We present the case of a man in his early 60 s with a chief complaint of a painful tongue ulcer. An ulcerated, indurated, and hemorrhagic lesion (23 × 14 mm) was found on the ventral tongue surface, near the oral floor. Palpation identified several swollen, mobile, elastic cervical lymph nodes, with no tenderness. We initially diagnosed tongue cancer; however, during a subsequent detailed examination for a malignant tumor, including biopsy and obtaining additional history, his disease was finally identified as primary syphilis with multiple swollen cervical lymph nodes. Oral amoxicillin and probenecid were started, and after 14 days, there was partial reduction in the size of the submandibular lymph nodes and the ulcer on the left tongue margin. The number of patients with syphilis in Japan increased by eight times from 2012 to 2018. We suggest that dentists consider primary syphilis as a differential diagnosis for oral refractory ulcer with induration and obtain a detailed patient history.


Subject(s)
Syphilis , Tongue Diseases , Tongue Neoplasms , Male , Female , Humans , Tongue Neoplasms/diagnosis , Tongue Neoplasms/pathology , Ulcer/diagnosis , Ulcer/pathology , Syphilis/diagnosis , Syphilis/pathology , Tongue Diseases/diagnosis , Tongue Diseases/pathology , Tongue/pathology
11.
Sci Rep ; 12(1): 21695, 2022 12 15.
Article in English | MEDLINE | ID: mdl-36522371

ABSTRACT

Mutations in p53 are common in human oral squamous cell carcinoma (OSCC). However, in previous analyses, only detection of mutant p53 protein using immunohistochemistry or mutations in some exons have been examined. Full length mutant p53 protein in many cases shows a loss of tumor suppressor function, but in some cases possibly shows a gain of oncogenic function. In this study, we investigate relationships of outcomes with the mutational spectrum of p53 (missense and truncation mutations) in whole exon in OSCC. Specimens from biopsy or surgery (67 cases) were evaluated using next-generation sequencing for p53, and other oncogenic driver genes. The data were compared with overall survival (OS) and disease-free survival (DFS) using univariate and multivariate analyses. p53 mutations were detected in 54 patients (80.6%), 33 missense mutations and 24 truncation mutations. p53 mutations were common in the DNA-binding domain (43/52) and many were missense mutations (31/43). Mutations in other regions were mostly p53 truncation mutations. We detected some mutations in 6 oncogenic driver genes on 67 OSCC, 25 in NOTCH1, 14 in CDKN2A, 5 in PIK3CA, 3 in FBXW7, 3 in HRAS, and 1 in BRAF. However, there was no associations of the p53 mutational spectrum with mutations of oncogenic driver genes in OSCC. A comparison of cases with p53 mutations (missense or truncation) with wild-type p53 cases showed a significant difference in lymph node metastasis. DFS was significantly poorer in cases with p53 truncation mutations. Cases with p53 truncation mutations increased malignancy. In contrast, significant differences were not found between cases with p53 missense mutations and other mutations. The p53 missense mutation cases might include cases with mostly similar function to that of the wild-type, cases with loss of function, and cases with various degrees of gain of oncogenic function.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Mouth Neoplasms/pathology , Carcinoma, Squamous Cell/pathology , Tumor Suppressor Protein p53/genetics , Squamous Cell Carcinoma of Head and Neck/genetics , DNA Mutational Analysis , Exons/genetics , Mutation , Head and Neck Neoplasms/genetics
12.
Front Cell Dev Biol ; 10: 864035, 2022.
Article in English | MEDLINE | ID: mdl-35573667

ABSTRACT

The sonic hedgehog (SHH) pathway regulates the development of the central nervous system in vertebrates. Aberrant regulation of SHH signaling pathways often causes neurodevelopmental diseases and brain tumors. In the cerebellum, SHH secreted by Purkinje cells is a potent mitogen for granule cell progenitors, which are the most abundant cell type in the mature brain. While a reduction in SHH signaling induces cerebellar structural abnormalities, such as hypoplasia in various genetic disorders, the constitutive activation of SHH signaling often induces medulloblastoma (MB), one of the most common pediatric malignant brain tumors. Based on the existing literature on canonical and non-canonical SHH signaling pathways, emerging basic and clinical studies are exploring novel therapeutic approaches for MB by targeting SHH signaling at distinct molecular levels. In this review, we discuss the present consensus on SHH signaling mechanisms, their roles in cerebellar development and tumorigenesis, and the recent advances in clinical trials for MB.

13.
Cancers (Basel) ; 13(22)2021 Nov 21.
Article in English | MEDLINE | ID: mdl-34830994

ABSTRACT

BACKGROUND: The surveillance methods oral squamous cell carcinoma (OSCC) patients may be chosen by considering the risk for recurrence, and it is important to establish appropriate methods during the period in which latent/dormant cancer cells become more apparent. To investigate the appropriate surveillance of patients with OSCC based on the individual risk for recurrence and/or metastasis, we performed a retrospective cohort study after the complete surgical resection of OSCC as the primary treatment. METHODS: The study was performed in 324 patients with OSCC who had been primarily treated with surgery from 2007 to 2020 at our hospital. We investigated the period, timing, and methods (visual examination, palpation and imaging using FDG-PET/CT or CECT) for surveillance in each case that comprised postsurgical treatment. RESULTS: Regarding the time to occurrence of postsurgical events, we found that half of cases of local recurrence, cervical lymph node metastasis, and distant metastasis occurred within 200 days, and 75% of all of these events occurred within 400 days. However, the mean time for second primary cancer was 1589 days. The postsurgical events were detected earlier by imaging examinations than they were by visual examination and palpation. CONCLUSIONS: For the surveillance of patients with OSCC after primary surgery, it is desirable to perform FDG-PET/CT within 3-6 months and at 1 year after surgery and to consider CECT as an option in between FDG-PET/CT, while continuing history and physical examinations for about 5 years based on individual risk assessment.

14.
Int J Mol Sci ; 22(20)2021 Oct 09.
Article in English | MEDLINE | ID: mdl-34681573

ABSTRACT

TSC-22 (TGF-ß stimulated clone-22) has been reported to induce differentiation, growth inhibition, and apoptosis in various cells. TSC-22 is a member of a family in which many proteins are produced from four different family genes. TSC-22 (corresponding to TSC22D1-2) is composed of 144 amino acids translated from a short variant mRNA of the TSC22D1 gene. In this study, we attempted to determine the intracellular localizations of the TSC22D1 family proteins (TSC22D1-1, TSC-22 (TSC22D1-2), and TSC22(86) (TSC22D1-3)) and identify the binding proteins for TSC22D1 family proteins by mass spectrometry. We determined that TSC22D1-1 was mostly localized in the nucleus, TSC-22 (TSC22D1-2) was localized in the cytoplasm, mainly in the mitochondria and translocated from the cytoplasm to the nucleus after DNA damage, and TSC22(86) (TSC22D1-3) was localized in both the cytoplasm and nucleus. We identified multiple candidates of binding proteins for TSC22D1 family proteins in in vitro pull-down assays and in vivo binding assays. Histone H1 bound to TSC-22 (TSC22D1-2) or TSC22(86) (TSC22D1-3) in the nucleus. Guanine nucleotide-binding protein-like 3 (GNL3), which is also known as nucleostemin, bound to TSC-22 (TSC22D1-2) in the nucleus. Further investigation of the interaction of the candidate binding proteins with TSC22D1 family proteins would clarify the biological roles of TSC22D1 family proteins in several cell systems.


Subject(s)
GTP-Binding Proteins/metabolism , Histones/metabolism , Nuclear Proteins/metabolism , Repressor Proteins/metabolism , Alternative Splicing , Cell Differentiation , Cell Line , Cell Nucleus/metabolism , Cytoplasm/metabolism , DNA Damage , HEK293 Cells , Humans , Mass Spectrometry , Mitochondria/metabolism , Protein Binding , Protein Interaction Maps
15.
Cancer Sci ; 112(8): 2948-2957, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34050694

ABSTRACT

Medulloblastoma is the most common malignant cerebellar tumor in children. Recent technological advances in multilayered 'omics data analysis have revealed 4 molecular subgroups of medulloblastoma (Wingless/int, Sonic hedgehog, Group3, and Group4). (Epi)genomic and transcriptomic profiling on human primary medulloblastomas has shown distinct oncogenic drivers and cellular origin(s) across the subgroups. Despite tremendous efforts to identify the molecular signals driving tumorigenesis, few of the identified targets were druggable; therefore, a further understanding of the etiology of tumors is required to establish effective molecular-targeted therapies. Chromatin regulators are frequently mutated in medulloblastoma, prompting us to investigate epigenetic changes and the accompanying activation of oncogenic signaling during tumorigenesis. For this purpose, we have used germline and non-germline genetically engineered mice to model human medulloblastoma and to conduct useful, molecularly targeted, preclinical studies. This review discusses the biological implications of chromatin regulator mutations during medulloblastoma pathogenesis, based on recent in vivo animal studies.


Subject(s)
Biomarkers, Tumor/genetics , Cerebellar Neoplasms/pathology , Epigenesis, Genetic , Medulloblastoma/pathology , Animals , Cerebellar Neoplasms/genetics , Chromatin/genetics , Gene Expression Regulation, Neoplastic , Genetic Engineering , Humans , Medulloblastoma/genetics , Mice , Mutation
16.
Cancer Discov ; 11(9): 2230-2247, 2021 09.
Article in English | MEDLINE | ID: mdl-33879448

ABSTRACT

Molecular groups of supratentorial ependymomas comprise tumors with ZFTA-RELA or YAP1-involving fusions and fusion-negative subependymoma. However, occasionally supratentorial ependymomas cannot be readily assigned to any of these groups due to lack of detection of a typical fusion and/or ambiguous DNA methylation-based classification. An unbiased approach with a cohort of unprecedented size revealed distinct methylation clusters composed of tumors with ependymal but also various other histologic features containing alternative translocations that shared ZFTA as a partner gene. Somatic overexpression of ZFTA-associated fusion genes in the developing cerebral cortex is capable of inducing tumor formation in vivo, and cross-species comparative analyses identified GLI2 as a key downstream regulator of tumorigenesis in all tumors. Targeting GLI2 with arsenic trioxide caused extended survival of tumor-bearing animals, indicating a potential therapeutic vulnerability in ZFTA fusion-positive tumors. SIGNIFICANCE: ZFTA-RELA fusions are a hallmark feature of supratentorial ependymoma. We find that ZFTA acts as a partner for alternative transcriptional activators in oncogenic fusions of supratentorial tumors with various histologic characteristics. Establishing representative mouse models, we identify potential therapeutic targets shared by ZFTA fusion-positive tumors, such as GLI2.This article is highlighted in the In This Issue feature, p. 2113.


Subject(s)
DNA-Binding Proteins/genetics , Ependymoma/genetics , Proteins/genetics , Supratentorial Neoplasms/genetics , Transcription Factors/genetics , Animals , Cell Line, Tumor , Disease Models, Animal , Ependymoma/pathology , Genomics , Humans , Mice , Supratentorial Neoplasms/pathology
17.
Invest New Drugs ; 39(3): 846-852, 2021 06.
Article in English | MEDLINE | ID: mdl-33449240

ABSTRACT

A retrospective cohort study was performed to investigate the effectiveness of preemptive postsurgical therapy with cetuximab for patients with a major risk of recurrence or metastasis after clinical complete resection of primary oral squamous cell carcinoma (OSCC). The study period was from 2007 to 2019 for patients treated at the Department of Oral and Maxillofacial Surgery, Dokkyo Medical University School of Medicine. OSCC patients with major risk (n = 88) in the follow-up period were divided into groups with no postsurgical treatment (NP group), with standard postsurgical treatment (SP group), and with postsurgical treatment including cetuximab (CP group), and prognosis were compared among those groups. The 5-year overall survival rate was significantly higher in patients who received postsurgical treatment with cetuximab (CP) compared to that in the other two groups ((CP vs. NP, p = 0.028; CP vs. SP, p = 0.042). Furthermore, we performed multivariate analysis to evaluate the effects of the main components of the treatment. Among CDDP, radiotherapy, and cetuximab, only cetuximab significantly contributed to improved survival by univariate analysis (crude HR:0.228, 95%CI:0.05-0.968, p = 0.045). cetuximab also showed the same tendency in multivariate analysis, although p value did not reach significant level (Adjusted HR: 0.233, 95%CI: 0.053-1.028, p = 0.054). The results suggest that the postsurgical treatment with cetuximab as a preemptive postsurgical therapy after complete surgical resection of a visible tumor is considerably effective for OSCC patients with major risk, in other words, invisible dormant metastasis.


Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Cetuximab/therapeutic use , Mouth Neoplasms/drug therapy , Squamous Cell Carcinoma of Head and Neck/drug therapy , Aged , Combined Modality Therapy , ErbB Receptors/antagonists & inhibitors , Female , Humans , Male , Middle Aged , Mouth Neoplasms/surgery , Retrospective Studies , Risk , Squamous Cell Carcinoma of Head and Neck/surgery , Treatment Outcome
18.
Genes Cells ; 25(12): 796-810, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33020978

ABSTRACT

A proper balance between proliferation and differentiation of cerebellar granule cell precursors (GCPs) is required for appropriate cerebellar morphogenesis. The Skp1-Cullin1-F-box (SCF) complex, an E3 ubiquitin ligase complex, is involved in polyubiquitination and subsequent degradation of various cell cycle regulators and transcription factors. However, it remains unknown how the SCF complex affects proliferation and differentiation of GCPs. In this study, we found that the scaffold protein Cullin1, and F-box proteins Skp2, ß-TrCP1 and ß-TrCP2 are expressed in the external granule layer (EGL). Knockdown of these molecules in the EGL showed that Cullin1, Skp2 and ß-TrCP2 enhanced differentiation of GCPs. We also observed accumulation of cyclin-dependent kinase inhibitor p27 in GCPs when treated with a Cullin1 inhibitor or proteasome inhibitor. Furthermore, knockdown of p27 rescued enhancement of differentiation by Cullin1 knockdown. These results suggest that the SCF complex is involved in the maintenance of the proliferative state of GCPs through p27 degradation. In addition, inhibition of Cullin1 activity also prevented cell proliferation and enhanced accumulation of p27 in Daoy cells, a cell line derived from the sonic hedgehog subtype of medulloblastoma. This suggested that excess degradation of p27 through the SCF complex causes overproliferation of medulloblastoma cells.


Subject(s)
Cerebellum/cytology , Neural Stem Cells/metabolism , Neurogenesis , S-Phase Kinase-Associated Proteins/metabolism , beta-Transducin Repeat-Containing Proteins/metabolism , Animals , Cell Line, Tumor , Cell Proliferation , Cells, Cultured , Cerebellum/metabolism , Cullin Proteins/metabolism , Cyclin-Dependent Kinase Inhibitor p27/metabolism , HEK293 Cells , Humans , Mice , Mice, Inbred ICR , Neural Stem Cells/cytology , S-Phase Kinase-Associated Proteins/genetics , Ubiquitination
19.
Genes Dev ; 34(17-18): 1161-1176, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32820036

ABSTRACT

Medulloblastoma is a malignant childhood brain tumor arising from the developing cerebellum. In Sonic Hedgehog (SHH) subgroup medulloblastoma, aberrant activation of SHH signaling causes increased proliferation of granule neuron progenitors (GNPs), and predisposes these cells to tumorigenesis. A second, cooperating genetic hit is often required to push these hyperplastic cells to malignancy and confer mutation-specific characteristics associated with oncogenic signaling. Somatic loss-of-function mutations of the transcriptional corepressor BCOR are recurrent and enriched in SHH medulloblastoma. To investigate BCOR as a putative tumor suppressor, we used a genetically engineered mouse model to delete exons 9/10 of Bcor (BcorΔE9-10 ) in GNPs during development. This mutation leads to reduced expression of C-terminally truncated BCOR (BCORΔE9-10). While BcorΔE9-10 alone did not promote tumorigenesis or affect GNP differentiation, BcorΔE9-10 combined with loss of the SHH receptor gene Ptch1 resulted in fully penetrant medulloblastomas. In Ptch1+/- ;BcorΔE9-10 tumors, the growth factor gene Igf2 was aberrantly up-regulated, and ectopic Igf2 overexpression was sufficient to drive tumorigenesis in Ptch1+/- GNPs. BCOR directly regulates Igf2, likely through the PRC1.1 complex; the repressive histone mark H2AK119Ub is decreased at the Igf2 promoter in Ptch1+/- ;BcorΔE9-10 tumors. Overall, our data suggests that BCOR-PRC1.1 disruption leads to Igf2 overexpression, which transforms preneoplastic cells to malignant tumors.


Subject(s)
Cerebellar Neoplasms/genetics , Gene Expression Regulation, Neoplastic/genetics , Hedgehog Proteins/metabolism , Medulloblastoma/genetics , Polycomb-Group Proteins/metabolism , Repressor Proteins/genetics , Animals , Carcinogenesis/genetics , Disease Models, Animal , Hedgehog Proteins/genetics , Humans , Mice , Mutation , Patched-1 Receptor/genetics , Polycomb-Group Proteins/genetics , Repressor Proteins/metabolism , Sequence Deletion
20.
Gene Expr Patterns ; 34: 119068, 2019 12.
Article in English | MEDLINE | ID: mdl-31437514

ABSTRACT

Cerebellar granule cell precursors (GCPs) and granule cells (GCs) constitute a good model system to investigate proliferation of neural precursors and differentiation of neurons. During development, GCPs proliferate in the outer external granule cell layer (outer EGL) and then exit the cell cycle in the inner EGL to become GCs, which inwardly migrate to the inner granule cell layer (IGL). Misregulation of GCP proliferation or GC differentiation leads to maldevelopment of the cerebellum and the formation of a cerebellar tumor, medulloblastoma. Despite many efforts in this field, the mechanisms underlying GC development remain elusive. In this study, we performed detailed immunostaining in the developing cerebellum, with particular focus on GCPs and GCs, looking at several transcription factors, signaling molecules, cell cycle regulators, some of which are known to regulate neural development. Interestingly, we found distinct distribution patterns of certain proteins within the outer and inner EGL, suggesting the existence of subpopulations of GCPs and GCs in those layers. This study provides a basis for future studies on the cerebellar GC development and medulloblastoma.


Subject(s)
Cerebellum/metabolism , Neurons/metabolism , Transcription Factors/metabolism , Animals , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Cycle , Cell Differentiation/physiology , Cell Division , Cell Proliferation , Immunohistochemistry/methods , Ki-67 Antigen/metabolism , Medulloblastoma/metabolism , Medulloblastoma/physiopathology , Mice , Mice, Inbred ICR , Neurogenesis/physiology , Signal Transduction
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