RESUMO
RNA sequencing (RNA-Seq) has become a widely adopted technique for studying gene expression. However, conventional RNA-Seq analyses rely on gene expression (GE) values that aggregate all the transcripts produced under a single gene identifier, overlooking the complexity of transcript variants arising from different transcription start sites or alternative splicing. Transcript variants may encode proteins with diverse functional domains, or noncoding RNAs. This study explored the implications of neglecting transcript variants in RNA-Seq analyses. Among the 1334 transcription factor (TF) genes expressed in mouse embryonic stem (ES) or trophoblast stem (TS) cells, 652 were differentially expressed in TS cells based on GE values (365 upregulated and 287 downregulated, ≥absolute 2-fold changes, false discovery rate (FDR) p-value ≤ 0.05). The 365 upregulated genes expressed 883 transcript variants. Further transcript expression (TE) based analyses identified only 174 (<20%) of the 883 transcripts to be upregulated. The remaining 709 transcripts were either downregulated or showed no significant changes. Meanwhile, the 287 downregulated genes expressed 856 transcript variants and only 153 (<20%) of the 856 transcripts were downregulated. The other 703 transcripts were either upregulated or showed no significant change. Additionally, the 682 insignificant TF genes (GE values < absolute 2-fold changes and/or FDR p-values > 0.05) between ES and TS cells expressed 2215 transcript variants. These included 477 (>21%) differentially expressed transcripts (276 upregulated and 201 downregulated, ≥absolute 2-fold changes, FDR p-value ≤ 0.05). Hence, GE based RNA-Seq analyses do not represent accurate expression levels due to divergent transcripts expression from the same gene. Our findings show that by including transcript variants in RNA-Seq analyses, we can generate a precise understanding of a gene's functional and regulatory landscape; ignoring the variants may result in an erroneous interpretation.
Assuntos
Perfilação da Expressão Gênica , Transcriptoma , Animais , Camundongos , Transcriptoma/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Trofoblastos/metabolismo , Análise de Sequência de RNA , Processamento Alternativo/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação da Expressão Gênica , Células-Tronco Embrionárias Murinas/metabolismoRESUMO
Increased activation of ovarian primordial follicles in Erß knockout (ErßKO) rats becomes evident as early as postnatal day 8.5. To identify the ERß-regulated genes that may control ovarian primordial follicle activation, we analyzed the transcriptome profiles of ErßKO rat ovaries collected on postnatal days 4.5, 6.5, and 8.5. Compared to wildtype ovaries, ErßKO ovaries displayed dramatic downregulation of Indian hedgehog (Ihh) expression. IHH-regulated genes, including Hhip, Gli1, and Ptch1, were also downregulated in ErßKO ovaries. This was associated with a downregulation of steroidogenic enzymes Cyp11a1, Cyp19a1, and Hsd17b1. The expression of Ihh remained very low in ErßKO ovaries despite the high levels of Gdf9 and Bmp15, which are known upregulators of Ihh expression in the granulosa cells of activated ovarian follicles. Strikingly, the downregulation of the Ihh gene in ErßKO ovaries began to disappear on postnatal day 16.5 and recovered on postnatal day 21.5. In rat ovaries, the first wave of primordial follicles is rapidly activated after their formation, whereas the second wave of primordial follicles remains dormant in the ovarian cortex and slowly starts activating after postnatal day 12.5. We localized the expression of Ihh mRNA in postnatal day 8.5 wildtype rat ovaries but not in the age-matched ErßKO ovaries. In postnatal day 21.5 ErßKO rat ovaries, we detected Ihh mRNA mainly in the activated follicles in the ovaries' peripheral regions. Our findings indicate that the expression of Ihh in the granulosa cells of the activated first wave of ovarian follicles depends on ERß.
Assuntos
Receptor beta de Estrogênio , Proteínas Hedgehog , Animais , Feminino , Ratos , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Folículo Ovariano/metabolismo , Ovário/metabolismo , RNA Mensageiro/metabolismoRESUMO
Loss of ERß increases primordial follicle growth activation (PFGA), leading to premature ovarian follicle reserve depletion. We determined the expression and gene regulatory functions of ERß in dormant primordial follicles (PdFs) and activated primary follicles (PrFs) using mouse models. PdFs and PrFs were isolated from 3-week-old Erß knockout (Erßnull) mouse ovaries, and their transcriptomes were compared with those of control Erßfl/fl mice. We observed a significant (≥2-fold change; FDR p-value ≤ 0.05) deregulation of approximately 5% of genes (866 out of 16,940 genes, TPM ≥ 5) in Erßnull PdFs; ~60% (521 out of 866) of the differentially expressed genes (DEGs) were upregulated, and 40% were downregulated, indicating that ERß has both transcriptional enhancing as well as repressing roles in dormant PdFs. Such deregulation of genes may make the Erßnull PdFs more susceptible to increased PFGA. When the PdFs undergo PFGA and form PrFs, many new genes are activated. During PFGA of Erßfl/fl follicles, we detected a differential expression of ~24% genes (4909 out of 20,743; ≥2-fold change; FDR p-value ≤ 0.05; TPM ≥ 5); 56% upregulated and 44% downregulated, indicating the gene enhancing and repressing roles of Erß-activated PrFs. In contrast, we detected a differential expression of only 824 genes in Erßnull follicles during PFGA (≥2-fold change; FDR p-value ≤ 0.05; TPM ≥ 5). Moreover, most (~93%; 770 out of 824) of these DEGs in activated Erßnull PrFs were downregulated. Such deregulation of genes in Erßnull activated follicles may impair their inhibitory role on PFGA. Notably, in both Erßnull PdFs and PrFs, we detected a significant number of epigenetic regulators and transcription factors to be differentially expressed, which suggests that lack of ERß either directly or indirectly deregulates the gene expression in PdFs and PrFs, leading to increased PFGA.
Assuntos
Receptor beta de Estrogênio , Folículo Ovariano , Feminino , Camundongos , Animais , Receptor beta de Estrogênio/metabolismo , Folículo Ovariano/metabolismo , Ovário/metabolismo , Regulação da Expressão Gênica , Transcriptoma , Camundongos KnockoutRESUMO
Adoptive transfer of genetically engineered chimeric antigen receptor (CAR) T cells is becoming a promising treatment option for hematological malignancies. However, T cell immunotherapies have mostly failed in individuals with solid tumors. Here, with a CRISPR-Cas9 pooled library, we performed an in vivo targeted loss-of-function screen and identified ST3 ß-galactoside α-2,3-sialyltransferase 1 (ST3GAL1) as a negative regulator of the cancer-specific migration of CAR T cells. Analysis of glycosylated proteins revealed that CD18 is a major effector of ST3GAL1 in activated CD8+ T cells. ST3GAL1-mediated glycosylation induces the spontaneous nonspecific tissue sequestration of T cells by altering lymphocyte function-associated antigen-1 (LFA-1) endocytic recycling. Engineered CAR T cells with enhanced expression of ßII-spectrin, a central LFA-1-associated cytoskeleton molecule, reversed ST3GAL1-mediated nonspecific T cell migration and reduced tumor growth in mice by improving tumor-specific homing of CAR T cells. These findings identify the ST3GAL1-ßII-spectrin axis as a major cell-intrinsic program for cancer-targeting CAR T cell migration and as a promising strategy for effective T cell immunotherapy.
Assuntos
Receptores de Antígenos Quiméricos , Animais , Camundongos , Linfócitos T CD8-Positivos , Linhagem Celular Tumoral , Movimento Celular , Imunoterapia Adotiva , Antígeno-1 Associado à Função Linfocitária , Espectrina , Humanos , FemininoRESUMO
Altered RNA expression of repetitive sequences and retrotransposition are frequently seen in colorectal cancer, implicating a functional importance of repeat activity in cancer progression. We show the nucleoside reverse transcriptase inhibitor 3TC targets activities of these repeat elements in colorectal cancer preclinical models with a preferential effect in p53-mutant cell lines linked with direct binding of p53 to repeat elements. We translate these findings to a human phase II trial of single-agent 3TC treatment in metastatic colorectal cancer with demonstration of clinical benefit in 9 of 32 patients. Analysis of 3TC effects on colorectal cancer tumorspheres demonstrates accumulation of immunogenic RNA:DNA hybrids linked with induction of interferon response genes and DNA damage response. Epigenetic and DNA-damaging agents induce repeat RNAs and have enhanced cytotoxicity with 3TC. These findings identify a vulnerability in colorectal cancer by targeting the viral mimicry of repeat elements. SIGNIFICANCE: Colorectal cancers express abundant repeat elements that have a viral-like life cycle that can be therapeutically targeted with nucleoside reverse transcriptase inhibitors (NRTI) commonly used for viral diseases. NRTIs induce DNA damage and interferon response that provide a new anticancer therapeutic strategy. This article is highlighted in the In This Issue feature, p. 1397.
Assuntos
Neoplasias Colorretais , DNA Polimerase Dirigida por RNA , Animais , Antivirais , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , DNA , Humanos , Interferons/metabolismo , Lamivudina , Estágios do Ciclo de Vida , RNA , DNA Polimerase Dirigida por RNA/metabolismo , Proteína Supressora de Tumor p53/genéticaRESUMO
OBJECTIVE: An association between race and formation of chalazion has yet to be objectively established. This study investigates race as a risk factor for chalazion and chalazion surgery. Understanding racial risk factors in formation of chalazion, recurrent chalazion, and chalazion requiring surgery (often with general anesthesia in children) informs decisions regarding eyelid hygiene, early topical medical therapy, and aggressiveness with oral antibiotic therapy for coexisting conditions such as blepharitis. METHODS: Demographic data was collected for all pediatric visits to the University of Wisconsin-Madison ophthalmology department from 2012-2019. Retrospective chart review was performed for the subset with chalazion. RESULTS: Of 28 433 minors, 584 had 1088 chalazia, a 2% overall rate. Chalazion was seen in 1.8% of non-Hispanic/Latino participants and 3.8% of Hispanic/Latino participants (p value <0.0001). Chalazion was seen in 1.7% of white participants, compared to 4.3% of American Indian or Alaska Native participants (p value <0.0001) and 4.0% of Asian participants (p value <0.0001). More than one chalazion was recorded in 31% of subjects without coexisting meibomian gland disease, blepharitis, or marginal keratitis, and in 56% (p < 0.0001) with one of these conditions. Repeated diagnoses of chalazion on separate encounters were seen in 17% without these conditions and in 33% (p < 0.0001) with one of these conditions. CONCLUSION: Hispanic/Latino, American Indian, and Asian participants developed chalazion at a rate higher than other racial/ethnic groups, whereas patients with meibomian gland disease or blepharitis are especially at risk for developing multiple chalazia on separate encounters. No group was more likely to require surgical intervention than any other.
Assuntos
Blefarite , Calázio , Blefarite/epidemiologia , Calázio/diagnóstico , Calázio/epidemiologia , Calázio/cirurgia , Criança , Pálpebras , Humanos , Estudos Retrospectivos , Fatores de RiscoRESUMO
This report presents two cases of epidemic keratoconjunctivitis (EKC)-associated dacryocystitis. Both patients presented with preseptal edema. Orbital computed tomography (CT) scans were performed out of concern for orbital cellulitis and revealed soft tissue edema involving the preseptal aspect of the eyelids and also the lacrimal sac. Both patients were initially diagnosed with bacterial preseptal cellulitis with dacryocystitis and admitted for treatment with intravenous antibiotics. After no improvement on antibiotics, both patients were noted to have exam findings consistent with viral conjunctivitis, and one patient had a positive conjunctival swab for adenovirus. Both patients were subsequently treated with topical steroids, and symptoms improved. EKC has previously been identified as a cause of acquired nasolacrimal duct obstruction and canalicular stenosis, and acute inflammation of the lacrimal apparatus may explain this link. Dacryocystitis may also be contributory to the copious tearing seen in patients with epidemic keratoconjunctivitis.
Assuntos
Infecções por Adenovirus Humanos/complicações , Dacriocistite/etiologia , Infecções Oculares Virais/complicações , Ceratoconjuntivite/complicações , Infecções por Adenovirus Humanos/diagnóstico por imagem , Adulto , Dacriocistite/diagnóstico por imagem , Infecções Oculares Virais/diagnóstico por imagem , Feminino , Humanos , Ceratoconjuntivite/diagnóstico por imagem , Obstrução dos Ductos Lacrimais/etiologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
Transcriptional profiling has defined pancreatic ductal adenocarcinoma (PDAC) into distinct subtypes with the majority being classical epithelial (E) or quasi-mesenchymal (QM). Despite clear differences in clinical behavior, growing evidence indicates these subtypes exist on a continuum with features of both subtypes present and suggestive of interconverting cell states. Here, we investigated the impact of different therapies being evaluated in PDAC on the phenotypic spectrum of the E/QM state. We demonstrate using RNA-sequencing and RNA-in situ hybridization (RNA-ISH) that FOLFIRINOX combination chemotherapy induces a common shift of both E and QM PDAC toward a more QM state in cell lines and patient tumors. In contrast, Vitamin D, another drug under clinical investigation in PDAC, induces distinct transcriptional responses in each PDAC subtype, with augmentation of the baseline E and QM state. Importantly, this translates to functional changes that increase metastatic propensity in QM PDAC, but decrease dissemination in E PDAC in vivo models. These data exemplify the importance of both the initial E/QM subtype and the plasticity of E/QM states in PDAC in influencing response to therapy, which highlights their relevance in guiding clinical trials.
RESUMO
Single-cell technologies have described heterogeneity across tissues, but the spatial distribution and forces that drive single-cell phenotypes have not been well defined. Combining single-cell RNA and protein analytics in studying the role of stromal cancer-associated fibroblasts (CAFs) in modulating heterogeneity in pancreatic cancer (pancreatic ductal adenocarcinoma [PDAC]) model systems, we have identified significant single-cell population shifts toward invasive epithelial-to-mesenchymal transition (EMT) and proliferative (PRO) phenotypes linked with mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling. Using high-content digital imaging of RNA in situ hybridization in 195 PDAC tumors, we quantified these EMT and PRO subpopulations in 319,626 individual cancer cells that can be classified within the context of distinct tumor gland "units." Tumor gland typing provided an additional layer of intratumoral heterogeneity that was associated with differences in stromal abundance and clinical outcomes. This demonstrates the impact of the stroma in shaping tumor architecture by altering inherent patterns of tumor glands in human PDAC.
Assuntos
Fibroblastos Associados a Câncer/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Microambiente Tumoral , Animais , Proliferação de Células , Técnicas de Cocultura , Transição Epitelial-Mesenquimal , Feminino , Células HEK293 , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas Quinases Ativadas por Mitógeno/metabolismo , RNA-Seq , Fator de Transcrição STAT3/metabolismo , Células Estromais/metabolismo , TransfecçãoRESUMO
Glioblastoma is the most common and lethal form of primary brain cancer. In the recurrent setting, bevacizumab is a common choice for salvage therapy. Loss of vision in patients initially treated with radiation at the time of diagnosis and later treated with bevacizumab at time of recurrence has been reported, and presumed to be a treatment-related optic neuropathy. Strikingly, only 1 case report described a postmortem biopsy to rule out tumor involvement of the optic tracts. We report the first case of recurrent glioblastoma infiltrating the prechiasmatic and chiasmatic optic nerve, which at the time of vision loss was presumed to be secondary to bevacizumab. It is noteworthy that the MRI findings in the previously reported bevacizumab/radiation-induced optic neuropathy cases (without pathology follow-up) are comparable to our patient.
RESUMO
BACKGROUND: Recent work has demonstrated early shedding of circulating epithelial cells (CECs) from premalignant intraductal papillary mucinous neoplasms (IPMNs). However, the potential use of CECs as a "liquid biopsy" for patients with IPMNs has been limited by antigen dependence of CEC isolation devices and the lack of robust detection biomarkers across CEC phenotypes. MATERIALS AND METHODS: We utilized a negative depletion microfluidic platform to purify CECs from contaminating leukocytes and coupled this platform with immunofluorescence, RNA in situ hybridization, and RNA sequencing (RNA-seq) detection and enumeration. RESULTS: Using established protein (EpCAM, cytokeratins) and novel noncoding RNA (HSATII, cytokeratins) biomarkers, we detected CECs in 88% of patients bearing IPMN lesions. RNA-seq analysis for MUC genes confirm the likely origin of these CECs from pancreatic lesions. CONCLUSION: Our findings increase the sensitivity of detection of these cells and therefore could have clinical implications for cancer risk stratification. IMPLICATIONS FOR PRACTICE: This work describes a high-sensitivity platform for detection of epithelial cells shed from preneoplastic lesions at high risk of malignant transformation. Further research efforts are underway to define the transcriptional programs that might allow discrimination between circulating cells released from tumors that will become malignant and cells released from tumors that will not. After further refinement, this combination of technologies could be deployed for monitoring and early detection of patients at high risk for developing new or recurrent pancreatic malignancies.
Assuntos
Adenocarcinoma Mucinoso/diagnóstico , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Papilar/diagnóstico , Células Epiteliais/patologia , Células Neoplásicas Circulantes/patologia , Neoplasias Pancreáticas/diagnóstico , Lesões Pré-Cancerosas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
Precise rare-cell technologies require the blood to be processed immediately or be stabilized with fixatives. Such restrictions limit the translation of circulating tumor cell (CTC)-based liquid biopsy assays that provide accurate molecular data in guiding clinical decisions. Here we describe a method to preserve whole blood in its minimally altered state by combining hypothermic preservation with targeted strategies that counter cooling-induced platelet activation. Using this method, whole blood preserved for up to 72 h can be readily processed for microfluidic sorting without compromising CTC yield and viability. The tumor cells retain high-quality intact RNA suitable for single-cell RT-qPCR as well as RNA-Seq, enabling the reliable detection of cancer-specific transcripts including the androgen-receptor splice variant 7 in a cohort of prostate cancer patients with an overall concordance of 92% between fresh and preserved blood. This work will serve as a springboard for the dissemination of diverse blood-based diagnostics.
Assuntos
Separação Celular/métodos , Microfluídica/métodos , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Preservação de Sangue/métodos , Estudos de Casos e Controles , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Masculino , Ativação Plaquetária , Neoplasias da Próstata/sangue , Neoplasias da Próstata/genética , Isoformas de Proteínas/sangue , Isoformas de Proteínas/genética , RNA Neoplásico/sangue , RNA Neoplásico/genética , Receptores Androgênicos/sangue , Receptores Androgênicos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de RNARESUMO
BACKGROUND: There are limited data analyzing the effectiveness of boceprevir (BOC) or telaprevir (TVR) in combination with pegylated interferon (PEG-IFN) plus ribavirin (RBV) in a real-life patient cohort. AIMS: In clinical trials, patients with chronic hepatitis C (CHC) treated with BOC or TVR plus PEG-IFN and RBV achieved sustained virological response (SVR) rates of 70 %. However, it is not clear whether similar results can be realized in routine practice. Our goal is to examine SVR rates of these triple regimens for CHC in a multicenter real-life patient cohort. METHODS: We retrospectively studied 200 consecutive CHC genotype 1 patients who were initiated on PEG-IFN, RBV, and either TVR (n = 113) or BOC (n = 87) from July 2011 to February 2014 at two US academic liver clinics, a Veterans Affairs liver clinic and a community gastroenterology clinic. RESULTS: Both BOC and TVR treatment groups were similar in regard to comorbidities, BMI, and HCV RNA levels. BOC patients were more likely to have cirrhosis than TVR patients (47 vs. 24 %, P = 0.001). SVR rates were low in both cohorts (40 % for BOC, 53 % for TVR, P = 0.05). On multivariate logistic regression, treatment adherence by the "80/80/80 rule," diagnosis of cirrhosis, and use of erythropoietin were statistically significant predictors for SVR. Of these, treatment adherence was the strongest predictor (OR 4.43, 95 % CI 2.8-6.06, P < 0.001). CONCLUSION: SVR was much lower in a real-life patient cohort than in clinical trials (53 % for TVR and 40 % for BOC, compared to 66-75 % in clinical trials).
Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Prolina/análogos & derivados , Adulto , Idoso , Quimioterapia Combinada , Feminino , Humanos , Interferons/uso terapêutico , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Prolina/uso terapêutico , Estudos Retrospectivos , Ribavirina/uso terapêutico , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Pancreas cancer is one of most aggressive human cancers with the survival rate for patients with metastatic pancreas cancer at 5-6 months. The poor survival demonstrates a clear need for better target identification, drug development and new therapeutic strategies. Recent discoveries have shown that the role for Notch pathway is important in both development and cancer. Its contribution to oncogenesis also involves crosstalks with other growth factor pathways, such as Akt and its modulator, PTEN. The mounting evidence supporting a role for Notch in cancer promotion and survival suggests that targeting this pathway alone or in combination with other therapeutics represents a promising therapeutic strategy. RESULTS: Using a pancreas cancer tissue microarray, we noted that Jagged1, Notch3 and Notch4 are overexpressed in pancreas tumors (26%, 84% and 31% respectively), whereas Notch1 is expressed in blood vessels. While there was no correlation between Notch receptor expression and survival, stage or tumor grade, Notch3 was associated with Jagged1 and EGFR expression, suggesting a unique relationship between Notch3 and Jagged1. Inhibition of the Notch pathway genetically and with gamma-secretase inhibitor (GSI) resulted in tumor suppression and enhanced cell death. The observed anti-tumor activity appeared to be through Akt and modulation of PTEN phosphorylation. We discovered that transcriptional regulation of RhoA by Notch is important for PTEN phosphorylation. Finally, the mTOR inhibitor Rapamycin enhanced the effect of GSI on RhoA expression, resulting in down regulation of phospho-Akt and increased in vitro tumor cytotoxity. CONCLUSIONS: Notch pathway plays an important role in maintaining pancreas tumor phenotype. Targeting this pathway represents a reasonable strategy for the treatment of pancreas cancers. Notch modulates the Akt pathway through regulation of PTEN phosphorylation, an observation that has not been made previously. Furthermore, we discovered that this regulation is dependent on RhoA/Rock1 activation. Enhanced phospho-Akt suppression when GSI is combined with rapamycin suggests that targeting both pathways will lead to a greater efficacy in the treatment of patients with pancreas cancer.
Assuntos
Antibióticos Antineoplásicos/farmacologia , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Receptores Notch/antagonistas & inibidores , Transdução de Sinais/genética , Sirolimo/farmacologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Antibióticos Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Nus , PTEN Fosfo-Hidrolase/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação , Receptores Notch/genética , Receptores Notch/metabolismo , Sirolimo/uso terapêuticoRESUMO
OBJECTIVE: To report an incident of rapid development of profound hypotension, differing from the time described in previous reports, during the infusion of rituximab chemotherapy in a patient without prior exposure to the drug. CASE SUMMARY: An 84-year-old white male with Rai stage IV chronic lymphocytic leukemia was prescribed rituximab 375 mg/m(2) by intravenous infusion. Rituximab 50 mg/h was initiated after premedication with acetaminophen, diphenhydramine, dexamethasone, and ondansetron 3 days into his hospital course. Five minutes after the infusion had begun, he experienced a significant decrease in blood pressure to 76/45 mm Hg, and the infusion was stopped. After 30 minutes, the blood pressure returned to normal. Rechallenge with rituximab 25 mg/h was attempted, but the blood pressure again declined and the patient experienced chills and rigors. The infusion was discontinued, and the symptoms resolved 1 hour later. DISCUSSION: Infusion-related adverse reactions associated with rituximab are reported at a higher rate than with other monoclonal antibodies. Hypotension with rituximab has been reported to occur 30 minutes to 2 hours after initiation of the infusion. In contrast, severe hypotension in our patient occurred within 5 minutes after the infusion was started in a patient with no previous exposure to the drug. While many studies hypothesize that cytokine release from lymphocytes and tumor cell agglutination might contribute to severe infusion-related reactions with rituximab, the mechanism of action is not yet known. Use of the Naranjo probability scale indicated that the hypotension was probably associated with rituximab administration. CONCLUSIONS: Awareness of the rapidity of this adverse effect in patients who have not received prior treatment with monoclonal antibodies is important during chemotherapy treatment.
Assuntos
Anticorpos Monoclonais Murinos/administração & dosagem , Anticorpos Monoclonais Murinos/efeitos adversos , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Hipotensão/induzido quimicamente , Idoso de 80 Anos ou mais , Humanos , Infusões Intravenosas , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , RituximabRESUMO
We have previously shown that a subset of mDpy-30, an accessory subunit of the nuclear histone H3 lysine 4 methyltransferase (H3K4MT) complex, also localizes at the trans-Golgi network (TGN), where its recruitment is mediated by the TGN-localized ARF guanine nucleotide exchange factor (ArfGEF) BIG1. Depletion of mDpy-30 inhibits the endosome-to-TGN transport of internalized CIMPR receptors and concurrently promotes their accumulation at the cell protrusion. These observations suggest mDpy-30 may play a novel role at the crossroads of endosomal trafficking, nuclear transcription and adhesion/migration. Here we provide novel mechanistic and functional insight into this association. First, we demonstrate a direct interaction between mDpy-30 and BIG1 and locate the binding region in the N-terminus of BIG1. Second, we provide evidence that the depletion or overexpression of mDpy-30 enhances or inhibits cellular adhesion/migration of glioma cells in vitro, respectively. A similar increase in cell adhesion/migration is observed in cells with reduced levels of BIG1 or other H3K4MT subunits. Third, knockdown of mDpy-30, BIG1, or the RbBP5 H3K4MT subunit increases the targeting of beta1 integrin to cell protrusions, and suppression of H3K4MT activity by depleting mDpy-30 or RbBP5 leads to increased protein and mRNA levels of beta1 integrin. Moreover, stimulation of cell adhesion/migration via mDpy-30 knockdown is abolished after treating cells with a function-blocking antibody to beta1 integrin. Taken together, these data indicate that mDpy-30 and its interacting proteins function as a novel class of cellular adhesion/migration modulators partially by affecting the subcellular distribution of endosomal compartments as well as the expression of key adhesion/migration proteins such as beta1 integrin.