Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 902
Filtrar
1.
Acta Crystallogr A Found Adv ; 77(Pt 2): 138-148, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33646200

RESUMO

The coordination sequence of a graph measures how many vertices the graph has at each distance from a fixed vertex and is a generalization of the coordination number. Here it is proved that the coordination sequence of the graph obtained from a crystal is of quasi-polynomial type, as had been postulated by Grosse-Kunstleve et al. [Acta Cryst. (1996), A52, 879-889].

2.
Oncoimmunology ; 9(1): 1838189, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33235818

RESUMO

We had conducted phase 1/2 studies of cancer vaccination therapy using neo-tumor antigens in patients with refractory/persistent cervical cancer (CC) and ovarian cancer (OC) to assess the feasibility and efficacy. Enrollees must be refractory/persistent disease for usual treatments with Human Leukocyte Antigen-A*0201 or A*2402. The targets were epitope peptides obtained from driver genes in surviving pathways as follows: for CC A*0201, peptides from Up Regulating Lung Cancer 10 gene (URLC10) and Hypoxia-inducible gene 2 (HIG-2) and for OC A*0201, HIG2, VEGFR (vascular epithelial growth factor receptor) 1 and 2 were used. For CC A*2402, Forkhead Box M1 (FOXM1), Maternal Embryonic Leucine zipper Kinase (MELK), and Holliday Junction Recognition Protein (HJURP) were used. For OC A*2402, cocktails of peptides from FOXM1, MELK, HJURP, VEGFR1, and VEGFR2 were used. Subcutaneous administration was performed with adjuvant weekly. The toxicity profiles and tumor-response were analyzed in eight-week interval. Sixty-six patients were accrued, and 64 were evaluable for adverse events (AEs), and 35 for response. AEs of G2/3 dermatologic reaction (DR) of injection site had been identified in 15.6% and no other severe AEs were detected. Response rate in OC and CC were 22.9% and 20%, respectively. Median overall survival showed longer in performance status (PS) 0 (versus PS1/2), in CRP negative (versus positive) and in DR positive (versus negative) such as 8.7 m versus 1.2 m (p < .001), 8.8 m versus 3.0 m (p < .05) and 10.2 m versus 1.2 m (p < .001), respectively. In conclusion, our vaccination therapy was feasible and effective in this cohort of patients.

3.
J Clin Biochem Nutr ; 67(2): 199-205, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33041518

RESUMO

Some patients with interstitial pneumonia (IP) have auto-antibodies, but do not fit the criteria for specific connective tissue diseases. Examination of auto-antibodies is recommended for diagnosis idiopathic pulmonary fibrosis. A prospective cohort study was performed in 285 patients with IP. Eleven auto-antibodies were assessed and patients were followed for 2 years. All 285 patients underwent the myositis panel test (MPT) for 11 auto-antibodies. Among them, 23.5% (67/285) of the patients had a positive MPT and 14.7% (42/285) had connective tissue diseases. Among the 49 MPT positive patients without connective tissue diseases, 29 patients (59.2%) were positive for Ro52, including 17 patients with Ro52 mono-positivity. Among interstitial pneumonia patients without connective tissue diseases, the Ro52 mono-positive patients showed worse at 2-years survival than those who were Ro52 negative (p = 0.022, HR = 5.88, 95% CI 1.29-26.75). Most of the Ro52 positive patients also showed a low titer of anti-nucleolar antibody. About 20% of IP patients had auto-antibodies detectable by the MPT, and Ro52 positive patients accounted for more than half of the MPT positive patients without connective tissue diseases. Detection of Ro52 auto-antibodies may be useful for assessing the risk of progression in idiopathic interstitial pneumonia patients without connective tissue diseases and a low anti-nucleolar antibody titer.

4.
Clin Epigenetics ; 12(1): 146, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33050946

RESUMO

Protein lysine methyltransferases (PKMTs) constitute a large family of approximately 50 chromatin modifiers that mono-, di- and/or tri-methylate lysine residues on histone and non-histone substrates. With the advent of The Cancer Genome Atlas, it became apparent that this family of chromatin modifiers harbors frequent genetic and expression alterations in multiple types of cancer. In this regard, past and ongoing preclinical studies have provided insight into the mechanisms of action of some of these enzymes, laying the ground for the ongoing development of PKMT inhibitors as novel anticancer therapeutics. The purpose of this review is to summarize existing data obtained by different research groups through immunohistochemical analysis of the protein expression levels of PKMTs, and their respective clinicopathologic associations. We focused on studies that used immunohistochemistry to associate protein expression levels of specific PKMTs, as well as several established histone methylation marks, with clinicopathologic features and survival outcomes in various cancer types. We also review ongoing clinical trials of PKMT inhibitors in cancer treatment. This review underscores the clinical relevance and potential of targeting the family of PKMT enzymes as the next generation of cancer therapy.

5.
Cancer Sci ; 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33075187

RESUMO

We present a study to evaluate the feasibility and clinical utility of amplicon-based Oncomine Pan-Cancer cell-free assay to detect circulating tumor DNA (ctDNA) in patients with early or advanced breast cancer. In this study, 109 early and metastatic breast cancer patients were recruited before the initiation of treatment. ctDNA mutation profiles were assessed through unique molecular tagging (UMT) and ultradeep next generation sequencing (NGS). For patients with mutations, DNA from corresponding white blood cells (WBC) was sequenced to exclude variants of clonal-hematopoietic (CH) origin. UMT targeted sequencing from plasma of 109 patients achieved a median total coverage of 55 498X and a median molecular coverage of 4187X. Among 53 ctDNA positive samples, 38% were mutation positive by WBC sequencing, indicating potentially false-positive results contributed by CH origin. Prevalence of CH-related mutations was associated with age (P = 7.51 × 10-4 ). After exclusion of CH mutations, ctDNA detection rates were 37% for local or locally advanced breast cancer (stage I-III) and 81% for metastatic or recurrent breast cancer. The ctDNA detection rate correlated with disease stage (P = 2.60 × 10-4 ), nodal spread (P = 6.49 × 10-3 ) and the status of distant metastases (P = 5.00 × 10-4 ). ctDNA variants were detected mostly in TP53, PIK3CA and AKT1 genes, with variants showing therapeutic relevance. This pilot study endorses the use of targeted NGS for non-invasive molecular profiling of breast cancer. Paired sequencing of plasma ctDNA and WBC should be implemented to improve accurate interpretation of liquid biopsy.

6.
J Gynecol Oncol ; 31(6): e93, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33078598

RESUMO

OBJECTIVE: Maternal embryonic leucine zipper kinase (MELK) is receiving an attention as a therapeutic target in various types of cancers. In this study, we aimed to evaluate the prognostic significance of MELK expression in ovarian cancer using clinical samples, and assessed the efficacy of a small molecule MELK inhibitor, OTS167, using patient-derived ovarian cancer cells as well as cell lines. METHODS: Expression levels of MELK in 11 ovarian cancer cell lines were confirmed by western blotting. Inhibitory concentration of OTS167 was determined by colorimetric assay. MELK messenger RNA (mRNA) expression was evaluated in 228 ovarian cancer patients by quantitative polymerase chain reaction. Growth inhibition of OTS167 was also evaluated using freshly-isolated primary ovarian cancer cells including spheroid formation condition. RESULTS: MELK mRNA expression was significantly higher in ovarian cancer than in normal ovaries (p<0.001), and high MELK mRNA expression was observed in patients with advanced stage, positive ascites cytology and residual tumor size. Patients with high MELK mRNA expression showed shorter progression-free survival (p=0.001). Expression of MELK was also confirmed in 10 of 11 ovarian cancer cell lines tested, and the half maximal inhibitory concentration of MELK inhibitor, OTS167, ranged from 9.3 to 60 nM. Additionally, OTS167 showed significant growth inhibitory effect against patient-derived ovarian cancer cells, regardless of their tumor locations, histologic subtypes and stages. CONCLUSIONS: We demonstrated MELK as both a prognostic marker and a therapeutic target for ovarian cancer using clinical ovarian cancer samples. MELK inhibition by OTS167 may be an effective approach to treat ovarian cancer patients.

7.
Ann Surg ; 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-33055588

RESUMO

OBJECTIVES: To elucidate the efficacy of adjuvant vaccine monotherapy using 3 Human Leukocyte Antigen (HLA)-A24-restricted tumor-specific peptide antigens for ESCC, upregulated lung cancer 10, cell division cycle associated 1, and KH domain-containing protein overexpressed in cancer 1. SUMMARY OF BACKGROUND DATA: ESCC patients with pathologically positive nodes (pN(+)) have a high risk for postoperative recurrence, despite curative resection after preoperative therapy. Subclinical micrometastases are an appropriate target for cancer vaccine. METHODS: This is a non-randomized prospective phase II clinical trial (UMIN000003557). ESCC patients curatively resected after preoperative therapy with pN(+) were allocated into the control and vaccine groups (CG and VG) according to the HLA-A status. One mg each of three epitope peptides was postoperatively injected 10 times weekly followed by 10 times biweekly to the VG. The primary and secondary endpoints were relapse-free survival (RFS) and esophageal cancer-specific survival (ECSS), respectively. RESULTS: Thirty were in the CG and 33 in the VG. No significant difference was observed in RFS between the CG and VG (5-year RFS: 32.5% vs 45.3%), but the recurrence rate significantly decreased with the number of peptides which induced antigen-specific cytotoxic T lymphocytes. The VG showed a significantly higher 5-year ECSS than the CG (60.0% vs 32.4%, P = 0.045) and this difference was more prominent in patients with CD8 and programmed death-ligand 1 double negative tumor (68.0% vs 17.7%, P = 0.010). CONCLUSIONS: Our cancer peptide vaccine might improve the survival of ESCC patients, which is warranted to be verified in the phase III randomized controlled study.

9.
BMC Cancer ; 20(1): 1014, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33081727

RESUMO

BACKGROUND: Peritoneal metastasis (PM) in gastric cancer (GC) is characterized by diffusely infiltrating and proliferating cancer cells accompanied by extensive stromal fibrosis in the peritoneal space. The prognosis of GC with PM is still poor regardless of the various current treatments. In order to elucidate the cause of difficulties in PM treatment, we compared the tumor immune microenvironment (TME) in primary and PM lesions in GC. In addition, a PM model with fibrous stroma was constructed using immunocompetent mice to determine whether its TME was similar to that in patients. METHODS: Immuno-histochemical analyses of infiltrating immune cells were performed in paired primary and PM lesions from 28 patients with GC. A C57BL/6 J mouse model with PM was established using the mouse GC cell line YTN16 either with or without co-inoculation of mouse myofibroblast cell line LmcMF with α-SMA expression. The resected PM from each mouse model was analyzed the immunocompetent cells using immunohistochemistry. RESULTS: The number of CD8+ cells was significantly lower in PM lesions than in primary lesions (P < 0.01). Conversely, the number of CD163+ cells (M2 macrophages) was significantly higher in PM lesions than in primary lesions (P = 0.016). Azan staining revealed that YTN16 and LmcMF co-inoculated tumors were more fibrous than tumor with YTN16 alone (P < 0.05). Co-inoculated fibrous tumor also showed an invasive growth pattern and higher progression than tumor with YTN16 alone (P = 0.045). Additionally, YTN16 and LmcMF co-inoculated tumors showed lower infiltration of CD8+ cells and higher infiltration of M2 macrophages than tumors with YTN16 alone (P < 0.05, P < 0.05). These results indicate that LmcMF plays as cancer-associated fibroblasts (CAFs) by crosstalk with YTN16 and CAFs contribute tumor progression, invasion, fibrosis, and immune suppression. CONCLUSIONS: This model is the first immunocompetent mouse model similar to TME of human clinical PM with fibrosis. By using this model, new treatment strategies for PM, such as anti-CAFs therapies, may be developed.

10.
Oncotarget ; 11(34): 3198-3207, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32922660

RESUMO

Liquid biopsy is a non-invasive tool to examine the genetic profile of tumors by identification of mutated circulating tumor DNA (ctDNA), which is often analyzed by next generation sequencing (NGS) or droplet digital PCR (ddPCR) assay. We first examined the ctDNA mutation in pre-operative plasma samples obtained from 154 colorectal cancer (CRC) and 46 gastric cancer (GC) patients, using the NGS-based panel assay. The overall detection rate of mutated ctDNA was 72.0% (144 of 200 patients), and the panel-based screening identified 207 and 47 mutations from CRC and GC patients, respectively. The ddPCR analysis was then performed on post-operative samples of 77 patients, and detection of mutated ctDNA was earlier than imaging-based diagnosis in all of 6 patients who showed the tumor recurrences after surgery. Our data also revealed that patients with positive post-operation ctDNA level showed significant shorter recurrence-free survival compared to the patients with negative ctDNA level (HR 14.9; 95% CI, 0.7-313.5; p < 0.0001). These findings suggested that screening of mutated ctDNA by liquid biopsy aids in identifying the patients at high risk of post-operative recurrence, and serial screening of ctDNA would allow to monitor the response after treatment and/or early detection of tumor recurrence.

11.
Sci Rep ; 10(1): 14341, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868796

RESUMO

Temperature is an important factor for the cambial growth in temperate trees. We investigated the way daily temperatures patterns (maximum, average and minimum) from late winter to early spring affected the timing of cambial reactivation and xylem differentiation in stems of the conifer Chamaecyparis pisifera. When the daily temperatures started to increase earlier from late winter to early spring, cambial reactivation occurred earlier. Cambium became active when it achieves the desired accumulated temperature above the threshold (cambial reactivation index; CRI) of 13 °C in 11 days in 2013 whereas 18 days in 2014. This difference in duration required for achieving accumulated temperature can be explained with the variations in the daily temperature patterns in 2013 and 2014. Our formula for calculation of CRI predicted the cambial reactivation in 2015. A hypothetical increase of 1-4 °C to the actual daily maximum temperatures of 2013 and 2014 shifted the timing of cambial reactivation and had different effects on cambial reactivation in the two consecutive years because of variations in the actual daily temperatures patterns. Thus, the specific annual pattern of accumulation of temperature from late winter to early spring is a critical factor in determining the timing of cambial reactivation in trees.

12.
Cancers (Basel) ; 12(8)2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32823942

RESUMO

The use of blood liquid biopsy is being gradually incorporated into the clinical setting of cancer management. The minimally invasive nature of the usage of cell-free DNA (cfDNA) and its ability to capture the molecular alterations of tumors are great advantages for their clinical applications. However, somatic mosaicism in plasma remains an immense challenge for accurate interpretation of liquid biopsy results. Clonal hematopoiesis (CH) is part of the normal process of aging with the accumulation of somatic mutations and clonal expansion of hematopoietic stem cells. The detection of these non-tumor derived CH-mutations has been repeatedly reported as a source of biological background noise of blood liquid biopsy. Incorrect classification of CH mutations as tumor-derived mutations could lead to inappropriate therapeutic management. CH has also been associated with an increased risk of developing cardiovascular disease and hematological malignancies. Cancer patients, who are CH carriers, are more prone to develop therapy-related myeloid neoplasms after chemotherapy than non-carriers. The detection of CH mutations from plasma cfDNA analysis should be cautiously evaluated for their potential pathological relevance. Although CH mutations are currently considered as "false-positives" in cfDNA analysis, future studies should evaluate their clinical significance in healthy individuals and cancer patients.

13.
Biomolecules ; 10(8)2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32824461

RESUMO

Although gastric cancer is one of the most common causes of cancer death in the world, mechanisms underlying this type of tumor have not been fully understood. In this study, we found that IQGAP3, a member of the IQGAP gene family, was significantly up-regulated in human gastric cancer starting from the early stages of tumor progression. Overexpression of IQGAP3 in 293T and NIH3T3 cells, which have no endogenous IQGAP3 expression, resulted in morphological change with multiple dendritic-like protrusions and enhanced migration. Overexpression of IQGAP3 also led to reduced cell-cell adhesion in 293T cells, likely as a result of its interactions with e-cadherin or ß-catenin proteins. Additionally, IQGAP3 accumulated along the leading edge of migrating cells and at the cleavage furrow of dividing cells. In contrast, suppression of IQGAP3 by short-interfering RNA (siRNA) markedly reduced invasion and anchorage-independent growth of MKN1 and TMK-1 gastric cancer cells. We further confirmed that IQGAP3 interacted with Rho family GTPases, and had an important role in cytokinesis. Taken together, we demonstrated that IQGAP3 plays critical roles in migration and invasion of human gastric cancer cells, and regulates cytoskeletal remodeling, cell migration and adhesion. These findings may open a new avenue for the diagnosis and treatment of gastric cancer.

14.
Am J Pathol ; 190(11): 2282-2289, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32702358

RESUMO

Idiopathic osteonecrosis of the femoral head (ONFH) is defined as necrosis of osteocytes due to a non-traumatic ischemia of the femoral head. Iatrogenic glucocorticoid administration and habitual alcohol intake are regarded as risk factors. It has been suggested that glucocorticoid-induced activation of platelets contributes to the local blood flow disturbance of the femoral head. Both activated platelets and alcohol can induce neutrophil extracellular traps (NETs). To determine the association of NETs with the development of idiopathic ONFH, surgically resected femoral heads of patients with idiopathic ONFH and osteoarthritis were assessed for existence of NET-forming neutrophils by immunofluorescence staining. NET-forming neutrophils were present in small vessels surrounding the femoral head of patients with idiopathic ONFH but not osteoarthritis. Moreover, Wistar-Kyoto rats were intravenously injected with NET-forming neutrophils or neutrophils without NET induction, and then the ischemic state of the tissue around the femoral head was evaluated by immunohistochemistry for hypoxia-inducible factor-1α. NET-forming neutrophils circulated into the tissue around the femoral head, and hypoxia-inducible factor-1α expression in the tissue was higher compared with that of rats intravenously administered with neutrophils without NET induction. Furthermore, ischemic change of osteocytes was observed in the femoral head of rats given an i.v. injection of NET-forming neutrophils. The collective findings suggest that NETs are possibly associated with the development of idiopathic ONFH.


Assuntos
Armadilhas Extracelulares/metabolismo , Necrose da Cabeça do Fêmur/metabolismo , Cabeça do Fêmur/metabolismo , Neutrófilos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Modelos Animais de Doenças , Feminino , Cabeça do Fêmur/irrigação sanguínea , Cabeça do Fêmur/patologia , Necrose da Cabeça do Fêmur/patologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Pessoa de Meia-Idade , Neutrófilos/patologia , Ratos , Ratos Endogâmicos WKY
15.
J Hum Genet ; 65(12): 1075-1082, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32699345

RESUMO

The coronavirus disease 2019 (COVID-19) outbreak, caused by SARS-CoV-2, has rapidly expanded to a global pandemic. However, numbers of infected cases, deaths, and mortality rates related to COVID-19 vary from country to country. Although many studies were conducted, the reasons of these differences have not been clarified. In this study, we comprehensively investigated 12,343 SARS-CoV-2 genome sequences isolated from patients/individuals in six geographic areas and identified a total of 1234 mutations by comparing with the reference SARS-CoV-2 sequence. Through a hierarchical clustering based on the mutant frequencies, we classified the 28 countries into three clusters showing different fatality rates of COVID-19. In correlation analyses, we identified that ORF1ab 4715L and S protein 614G variants, which are in a strong linkage disequilibrium, showed significant positive correlations with fatality rates (r = 0.41, P = 0.029 and r = 0.43, P = 0.022, respectively). We found that BCG-vaccination status significantly associated with the fatality rates as well as number of infected cases. In BCG-vaccinated countries, the frequency of the S 614G variant had a trend of association with the higher fatality rate. We also found that the frequency of several HLA alleles, including HLA-A*11:01, were significantly associated with the fatality rates, although these factors were associated with number of infected cases and not an independent factor to affect fatality rate in each country. Our findings suggest that SARS-CoV-2 mutations as well as BCG-vaccination status and a host genetic factor, HLA genotypes might affect the susceptibility to SARS-CoV-2 infection or severity of COVID-19.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/genética , Infecções por Coronavirus/mortalidade , Pneumonia Viral/genética , Pneumonia Viral/mortalidade , Fatores Etários , Vacina BCG/genética , Vacina BCG/uso terapêutico , Betacoronavirus/classificação , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Epitopos/genética , Genoma Viral , Saúde Global , Antígenos HLA-A/genética , Antígenos HLA-A/imunologia , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Humanos , Mutação , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Glicoproteína da Espícula de Coronavírus/genética
16.
Immunol Invest ; : 1-18, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32660279

RESUMO

Chemorefractory ovarian cancer has limited therapeutic options. Hence, new types of treatment including neoantigen-specific immunotherapy need to be investigated. Neoantigens represent promising targets for personalized cancer immunotherapy. We here describe the clinical and immunological effects of a neoantigen peptide-loaded DC-based immunotherapy in a patient with recurrent and chemoresistant ovarian cancer. A 71-year-old female patient with chemorefractory ovarian cancer and malignant ascites received intranodal vaccination of DCs loaded with four neoantigen peptides that were predicted by our immunogenomic pipeline. Following four rounds of vaccinations with this therapy, CA-125 levels were remarkably declined and tumor cells in the ascites were also decreased. Concordantly, the tumor-related symptoms such as respiratory discomfort improved without any adverse reactions. The reactivity against one HLA-A2402-restricted neoantigen peptide derived from a mutated PPM1 F protein was detected in lymphocytes from peripheral blood by IFN-γ ELISPOT assay. Furthermore, the neoantigen (PPM1 F mutant)-specific TCRs were detected in the tumor-infiltrating T lymphocytes post-vaccination. Our results showed that vaccination with intranodal injection of neoantigen peptide-loaded DCs may have clinical and immunological impacts on cancer treatment.

18.
Gan To Kagaku Ryoho ; 47(6): 989-992, 2020 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-32541181

RESUMO

A 61-year-old man underwent CapeOX plus bevacizumab chemotherapyafter right hemicolectomyfor metastatic ascending colon cancer. On the 7th dayafter the first administration, he had sudden abdominal pain and nausea. Contrast-enhanced computed tomographyrevealed aortic thrombosis and a superior mesenteric artery(SMA)embolism that was considered to be associated with bevacizumab. Bevacizumab was discontinued and anticoagulation therapyusing heparin and urokinase was performed. Brain infarction of the left middle cerebral arteryoccurred on the 15th dayafter the first administration and thrombectomywas performed. Anticoagulation therapyusing heparin, bayaspirin, and edoxaban tosilate hydrate was performed. The aortic thrombosis and SMA embolism resolved with treatment, but the patient died following an increase in peritoneal dissemination. It should be noted that unexpectedlysevere aortic thrombosis occurred during the first administration of CapeOX plus bevacizumab for metastatic colon cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias do Colo , Trombose , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab , Capecitabina , Neoplasias do Colo/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos , Oxaliplatina , Trombose/induzido quimicamente
19.
Clin Chem ; 66(7): 946-957, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516802

RESUMO

BACKGROUND: Blood-based analysis of circulating tumor DNA (ctDNA) is a promising tool for cancer screening, monitoring relapse/recurrence and evaluating response to treatment. Although plasma is widely used to obtain ctDNA, biorepositories worldwide possess a huge number of serum samples and comparative studies on the use of serum vs plasma as ctDNA sources are essential. METHODS: We analyzed cell-free DNA (cfDNA) from matched EDTA-plasma and serum samples from healthy donors and patients with colorectal or lung cancer, and used targeted next-generation sequencing to evaluate mutation detection efficiency and reproducibility. Matched samples from healthy individuals were spiked with reference oligonucleotides and sequenced using the Ion-S5 Oncomine-Pan-Cancer panel. Detection efficiency in matched samples from patients with cancer was evaluated using 2 distinct gene panels and compared to mutations found in tissue-biopsy samples at diagnosis. RESULTS: Mean total cfDNA was 55% higher in serum samples and the presence of longer DNA fragments was significantly increased in serum compared with plasma samples (P = 0.0001 to 0.015). Spiked mutated nucleotides were detected in both samples, but allele frequencies (AF) were approximately half in serum compared with plasma, suggesting ctDNA from serum was more diluted by DNA of noncancerous origins. Matched samples from patients with cancer revealed that up to 44.8% of mutations with low AF were missed in serum samples and concordance rates with somatic mutations found in tissue biopsy at diagnosis was better in plasma samples. CONCLUSION: The use of serum in retrospective studies should consider the limitations for detecting low AF mutations. Plasma is clearly preferable for prospective clinical applications of liquid biopsy.

20.
Neoplasia ; 22(8): 283-293, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32497898

RESUMO

Squamous cell carcinoma of the head and neck (SCCHN) is a malignancy with poor outcomes, thus novel therapies are urgently needed. We recently showed that WHSC1 is necessary for the viability of SCCHN cells through H3K36 di-methylation. Here, we report the identification of its novel substrate, histone H1, and that WHSC1-mediated H1.4K85 mono-methylation may enhance stemness features in SCCHN cells. To identify proteins interacting with WHSC1 in SCCHN cells, WHSC1 immunoprecipitation and mass spectrometry identified H1 as a WHSC1-interacting candidate. In vitro methyltransferase assays showed that WHSC1 mono-methylates H1 at K85. We generated an H1K85 mono-methylation-specific antibody and confirmed that this methylation occurs in vivo. Sphere formation assays using SCC-35 cells stably expressing either wild-type (FLAG-H1.4-WT) or mutated (FLAG-H1.4K85A) vector with lysine 85 to alanine substitution which is not methylated, indicated a higher number of spheres in SCC-35 cells expressing the wild type than those with the mutant vector. SCC-35 cells expressing the wild type H1.4 proliferated faster than those expressing the mutated vector. RNA sequencing, RT-PCR and Western blotting of the FLAG-H1.4-WT or FLAG-H1.4K85A SCC-35 cells revealed that OCT4 levels were higher in wild type compared to mutant cells. These results were reproduced in SCC-35 cells genetically modified with CRISPR to express H1.4K85R. Chromatin immunoprecipitation showed that FLAG-H1.4K85A had decreased occupancy in the OCT4 gene compared to FLAG-H1.4-WT. This study supports that WHSC1 mono-methylates H1.4 at K85, it induces transcriptional activation of OCT4 and stemness features in SCCHN cells, providing rationale to target H1.4K85 mono-methylation through WHSC1 in SCCHN.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...