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1.
Waldenstr?m macroglobulinemia (WM) is a neoplasm of mature IgM-expressing B-lymphocytes that is characterized by the occurrence of a monoclonal IgM (mIgM) paraprotein in blood serum and the infiltration of hematopoietic bone marrow with malignant lymphoplasmacytic cells. WM remains incurable despite the development of new therapeutic options. Owing in large measure to having a low incidence, indolent clinical course and good long-term control with proper clinical management, WM has not been investigated as extensively as other B-lineage neoplasms. Major knowledge gaps in our understanding of the natural history of WM include the cell of origin. With that shortcoming in mind, here we discuss the significance of a specific gain-of-function mutation in the adapter protein, myeloid differentiation primary response 88 (MYD88), that occurs with near-complete penetrance in WM and suggests that tumor development is under strong selective pressure for elevated MYD88 signaling. This provides an intriguing link to IgM memory B-cells, which comprise two types of B-lymphocytes ( natural effector IgM+IgD+ cells and IgM-only IgM+IgD- cells ) that depend, in part, on MYD88 signaling and constitute intriguing candidates for WM’s cell of origin. We review the features and developmental history of IgM memory in greater depth and propose that WM may be derived from primitive innate-like B-cells ( marginal zone B-cells and B1 B-cells ) that feed the IgM memory compartment. We conclude with a model of MYD88-dependent tumor development in the mature B-cell lineage that considers two different ( convergent or divergent) oncogenesis pathways with respect to the cells of origin.  相似文献   

2.
Waldenstr?m macroglobulinemia (WM) is a low-grade lymphoplasmacytic lymphoma of mature IgM+ B-lymphocytes that remains incurable despite recent practice-altering therapeutic advances and refinements in patient care. Defining features of WM include symptoms that can either be attributed to the extent and site of tissue infiltration by tumor cells or the magnitude and immunological specificity of the monoclonal serum IgM (paraprotein). Current guidelines for the therapeutic stratification of patients with newly diagnosed WM recommend BR (bendamustin-rituximab) for bulky and/or symptomatic disease. DRC (dexamethasone-rituximab-cyclophosphamide) is a good treatment option for relapsed or refractory WM. Ibrutinib – a small-drug inhibitor of Bruton tyrosine kinase, approved for WM treatment in the United States and Europe in 2015 – is particularly effective for tumors that harbor the hallmark MYD88L265P mutation. Plasma exchange is indicated in patients with IgM-dependent hyperviscosity syndrome. The potential development of novel drugs and combination regimens generates promise that the future of patients with WM is bright.  相似文献   

3.
Waldenstr?m macroglobulinemia (WM) is an incurable low-grade lymphoplasmacytic lymphoma of mature IgM+ B-lymphocytes that warrants additional research to increase therapeutic options, enhance quality of life, and improve survival of patients with WM. Here we concluded a miniseries of short reviews on the diagnosis and treatment [1], natural history [2] and putative cell-of-origin of WM [3] with a brief survey of preclinical experimental model systems available for fundamental and translational research studies on this enigmatic neoplasm. The model systems comprise of: ① continuous tumor cell lines, three of which are well authenticated and demonstrated to be derived from the patient''s index tumor; ② human-in-mouse xenografts that rely on immunodeficient laboratory mice, adapted to carry small fragments of implanted human bone, to provide a suitable microenvironment for incoming lymphoma cells; and ③ genetically engineered mouse models (GEMMs) of neoplastic B-cell development, in which WM-like tumors arise spontaneously in the presence of fully functional innate and adaptive immune systems. Because none of the models developed thus far are perfect, additional efforts are required to achieve a better preclinical representation of disease characteristics of WM. To achieve that goal, the active involvement of basic and clinical research experts from China is called for, so novel drugs and immunotherapies for WM will reach clinics sooner, thereby ensuring the future of patients with WM will be brighter.  相似文献   

4.
Pancreatic cancer(PC) has been one of the deadliest of all cancers, with almost uniform lethality despite aggressive treatment. Recently, there have been important advances in the molecular, pathological and biological understandingof pancreatic cancer. Even after the emergence of recent new targeted agents and the use of multiple therapeutic combinations, no treatment option is viable in patients with advanced cancer. Developing novel strategies to target progression of PC is of intense interest. A small population of pancreatic cancer stem cells(CSCs) has been found to be resistant to chemotherapy and radiation therapy. CSCs are believed to be responsible for tumor initiation, progression and metastasis. The CSC research has recently achieved much progress in a variety of solid tumors, including pancreatic cancer to some extent. This leads to focus on understanding the role of pancreatic CSCs. The focus on CSCs may offer new targets for prevention and treatment of this deadly cancer. We review the most salient developments in important areas of pancreatic CSCs. Here, we provide a review of current updates and new insights on the role of CSCs in pancreatic tumor progression with special emphasis on Dcl K1 and Lgr5, signaling pathways altered by CSCs, and the role of CSCs in prevention and treatment of PC.  相似文献   

5.
The perception of pain involves the activation of the spinal pathway as well as the supra-spinal pathway,which targets brain regions involved in affective and cognitive processes.Pain and emotions have the capacity to influence each other reciprocally;negative emotions,such as depression and anxiety,increase the risk for chronic pain,which may lead to anxiety and depression.The amygdala is a key-player in the expression of emotions,receives direct nociceptive information from the parabrachial nucleus,and is densely innervated by noradrenergic brain centers.In recent years,the amygdala has attracted increasing interest for its role in pain perception and modulation.In this review,we will give a short overview of structures involved in the pain pathway,zoom in to afferent and efferent connections to and from the amygdala,with emphasis on the direct parabrachio-amygdaloid pathway and discuss the evidence for amygdala’s role in pain processing and modulation.In addition to the involvement of the amygdala in negative emotions during the perception of pain,this brain structure is also a target site for many neuromodulators to regulate the perception of pain.We will end this article with a short review on the effects of noradrenaline and its role in hypoalgesia and analgesia.  相似文献   

6.
The enigmatic role of angiopoietin-1 in tumor angiogenesis   总被引:13,自引:0,他引:13  
A tumor vasculature is highly unstable and immature, characterized by a high proliferation rate of endothelial cells, hyper-permeability, and chaotic blood flow. The dysfunctional vasculature gives rise to continual plasma leakage and hypoxia in the tumor, resulting in constant on-sets of inflammation and angiogenesis. Tumors are thus likened to wounds that will not heal. The lack of functional mural cells, including pericytes and vascular smooth muscle cells, in tumor vascular structure contributes significantly to the abnormality of tumor vessels. Angiopoietin-1 (Ang 1) is aphysiological angiogenesis promoter during embryonic development. The function of Angl is essential to endothelial cell survival, vascular branching, and pericyte recruitment. However, an increasing amount of experimental data suggest that Angl-stimulated association of mural cells with endothelial cells lead to stabilization of newly formed blood vessels. This in turn may limit the otherwise continuous angiogenesis in the tumor, and consequently give riseto inhibition of tumor growth. We discuss the enigmatic role of Angl in tumor angiogenesis in this review.  相似文献   

7.
The role of macroautophagy (hereafter autophagy) in cancer biology and response to clinical intervention is complex. It is clear that autophagy is dysregulated in a wide variety of tumor settings, both during tumor initiation and progression, and in response to therapy. However, the pleiotropic mechanistic roles of autophagy in controlling cell behavior make it difficult to predict in a given tumor setting what the role of autophagy, and, by extension, the therapeutic outcome of targeting autophagy, might be. In this review we summarize the evidence in the literature supporting pro- and anti-tumorigenic and -therapeutic roles of autophagy in cancer. This overview encompasses roles of autophagy in nutrient management, cell death, cell senescence, regulation of proteotoxic stress and cellular homeostasis, regulation of tumor-host interactions and participation in changes in metabolism. We also try to understand, where possible, the mechanistic bases of these roles for autophagy. We specifically expand on the emerging role of genetically- engineered mouse models of cancer in shedding light on these issues in vivo. We also consider how any or all of the above functions of autophagy proteins might be targetable by extant or future classes of pharmacologic agents. We conclude by briefly exploring non-canonical roles for subsets of the key autophagy proteins in cellular processes, and how these might impact upon cancer.  相似文献   

8.
Aberrant expression of microRNA-34a (miR-34a) has been reported to be involved in the tumorigenesis and progression of various classes of malignancies. However, its role in colorectal cancer (CRC) has not been completely clarified. In the current study, we have investigated the clinical significance of miR-34a. MiR-34a expression in forty-three cases of colorectal cancer tissues decreased significantly compared to that in the adjacent non-tumorous colorectal tissues (P<0.05), as detected by real-time quantitative RT-PCR (qRT-PCR). Significantly, the expression of miR-34a was correlated with infiltration depth and clinical TNM stage (P <0.05). The miR-34a however had no correlation with other features, such as age, gender, site, tumor sizes, lymph node metastasis, serous membrane infiltration ( all P> 0.05). MiR-34a is a tumor suppressor miRNA that plays a vital role in the oncogenesis and progression of colorectal cancer. This study suggests that miR-34a may be a new tumor marker or prognostic factor in colorectal cancer. The strategies to increase miR-34a level might be a critical targeted therapy for CRC in the future.  相似文献   

9.
In adults, the presence of the BRAF~(V600E) mutation in papillary thyroid cancer(PTC) has been demonstrated to be strongly associated with aggressive cancer-cell characteristics and poor patient prognosis. In contrast, the frequency of this mutation in pediatric PTC has undergone limited study, and the few available estimates range from 0 to 63%. Furthermore, the role of the BRAF~(V600E) mutation in pediatric PTC is controversial; thus, the present study aimed to investigate the prevalence and role of the BRAF~(V600E) mutation in48 pediatric patients with PTC, aged 3–13 years. Of these patients, 41 were diagnosed with classic PTC, five were found to have a follicular variant of PTC, and two to exhibit a diffuse sclerosing PTC variant. The BRAF~(V600E) mutation was identified to be present in 35.4% of the 48 analyzed patients, and in 41.5% of the patients diagnosed with classical PTC. Furthermore, the presence of the BRAF~(V600E) mutation was found to be associated with a patient age at diagnosis of less than ten years(P=0.011), the performance of a thyroidectomy(P=0.03), exhibited tumor multifocality(P=0.02) and/or extra-thyroidal invasion(P=0.003), and both a low MACIS(Metastases, Age, Completeness of resection, Invasion, Size)(P=0.036) and AMES(Age, Metastasis, Extent of tumor,Size)(P=0.001)score. Together, these data suggest that the presence of the BRAF~(V600E) mutation may be negatively correlated with partial aggressive clinicopathological features of pediatric PTC.  相似文献   

10.
Lectins are powerful stimulants of quiescent peripheral blood lymphocytes. They can induce blast transformation leading to mitosis of these cells in vitro. We report here the dose-dependent proliferative curve for human peripheral blood monouclear cells (PBMC) stimulated by the lectin amansin, from Amansia multifida. Amansin stimulated proliferation of (PBMC) at relatively low concentrations (3.12 to 12.5 μg mL-1). We observed also a gradual reduction in mitogenic capacity with progressive increase in the lectin concentration above 12.5 μg mL-1. This decrease in the mitogenic potential did not result from a toxic effect on the cells, and was predominant at a lectin concentration above 50 μg mL-1. This decrease in lymphocyte proliferation could be blocked by avidin and could not be overcome by IL-2 or another lectin (Con Br) at stimulatory concentrations. Additionally, we observed that cells incubated at stimulatory concentrations of amansin produced IFN-γ. Analysis of the culture supernatants established a direct correlation between the IFN-γ and the mitogenic and anti-mitogenic capacity of amansin. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

11.
Chronic hepatitis B virus(HBV)infection is one of the major causes of hepatocellularcarcinoma(HCC),and the HBV X(HBx)gene plays a critical role in the molecular pathogenesis ofHBV-related HCC.We have investigated whether there are particular HBx gene mutations associated withHCC in patients from southern China.The HBx gene was examined in 51 paraffin-embedded tumor tissuesamples from patients with HCC and 25 serum samples from the HBV carrier by nested polymerase chainreaction(PCR),single-stranded conformational polymorphism and heteroduplex analysis.The HBx geneswith potentially important mutations from tumor tissue samples were cloned,sequenced and aligned withthe published HBx gene sequence.HBV genotypes in tumor tissue samples were analyzed by nested PCR.Analyses of HBx gene polymorphism showed that 31.3% of HBx gene fragments in tumor tissue sampleshad a special pattern.A common deletion at nt 382-400 of the HBx gene accompanied by 29 point mutationswas detected in four randomly selected tumor tissue samples with this pattern which caused a frame-shiftin the HBx open reading frame with a new stop codon at nt 1818,resulting in an HBx polypeptide chaintruncated at the C end in these cases.Among the four randomly selected samples,three were HBV genotypeB,and one was not detected by our present assay.In another tumor tissue sample,amplification of thefull-length HBx gene yielded a shorter fragment.Sequencing of this fragment revealed a 264 bp deletionbetween nt 1577 and 1840 of the HBV gene.These results suggest that HBx gene mutation occurs frequentlyin HCC samples,and the deletion at nt 382-400 of the HBx gene might play a role in carcinogenesis of HCCin southern China.  相似文献   

12.
Diego blood antigens are important antigens in Mongoloid people and native South Americans owing to the Dia positivity rate found in these populations. However, the prevalence of Dia+ is different among native populations of America and China. Our study reviewed the genotype, phenotype, and alloantibody titre of Diego blood group antigens to explain the existence of the dosage effect for Diego antigens. The prevalence of Dia+ varied from 2.26% to 10.43% in the Chinese population was lower than that observed in Native Americans living in USA, Brazil, and Venezuela. The Di(a+b-)/Di(a+b+) ratio in the Chinese was 0.0044~0.0268, which was also lower than that observed in native Americans at 0.0203–0.1628, indicating that the major allele was Di(a+b+) in Dia+Chinese or Asians. We also collected Di(a+b-), Di(a+b+), and Di(a-b+) samples from Chinese samples to examine the agglutinin titres with anti-Dia and anti-Dib and the results supported the existence of the dosage effect for Diego antigens. The agglutinin titres of anti-Dia in Di(a+b+) specimens were lower than those in Di(a+b-) specimens, and agglutinin titres of anti-Dib in Di(a+b+) specimens were lower than those in Di(a-b+) specimens. Alloantibodies against Dia and Dib antigen are majorly responsible for haemolytic disease of the new-born and anti-Dia reactions resulting in stillborn foetus and transfusion reactions, such as fever and rash,were also reported in the Chinese population.  相似文献   

13.
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15.
He Y  Dong W J  Guo X Y  Dan L 《农业工程》2007,27(12):5086-5092
The characteristics of terrestrial growth in China and its relationship with various climatic factors (e.g. temperature, precipitation and radiation) were investigated by using the data collected with the Moderate Resolution Imaging Spectroradiometer (MODIS). These data were collected once every 8 days during 2000–2003 and then again in 2005. The average annual gross primary production (GPP) in China during this period ranged from 0 to 3252.6 gC·m?2·a?1 with an average value of 491.1 gC·m?2·a?1. The maximum GPP values were observed over the regions of Yunnan, Hainan and Taiwan, and the southeast coastal areas, while the minimum values were observed in the cold and arid regions of the Tibetan Plateau, Xinjiang and Inner Mongolia. Correlation analysis showed that temperature was the primary factor influencing this terrestrial growth, while precipitation played a secondary role. However, only the terrestrial growth that occurred in southern China was affected by radiation. The correlation coefficients of GPP with temperature and precipitation decreased from northern to southern China and were negatively correlated with the distribution of the associated climatic factors within China. Furthermore, the correlation coefficient of GPP with cloud contents was observed to increase from northern to southern China.  相似文献   

16.
The characteristics of terrestrial growth in China and its relationship with various climatic factors (e.g. temperature, precipitation and radiation) were investigated by using the data collected with the Moderate Resolution Imaging Spectroradiometer (MODIS). These data were collected once every 8 days during 2000–2003 and then again in 2005. The average annual gross primary production (GPP) in China during this period ranged from 0 to 3252.6 gC·m?2·a?1 with an average value of 491.1 gC·m?2·a?1. The maximum GPP values were observed over the regions of Yunnan, Hainan and Taiwan, and the southeast coastal areas, while the minimum values were observed in the cold and arid regions of the Tibetan Plateau, Xinjiang and Inner Mongolia. Correlation analysis showed that temperature was the primary factor influencing this terrestrial growth, while precipitation played a secondary role. However, only the terrestrial growth that occurred in southern China was affected by radiation. The correlation coefficients of GPP with temperature and precipitation decreased from northern to southern China and were negatively correlated with the distribution of the associated climatic factors within China. Furthermore, the correlation coefficient of GPP with cloud contents was observed to increase from northern to southern China.  相似文献   

17.
Mitochondrial DNA(mt DNA) variation has been implicated in many common complex diseases, but inconsistent and contradicting results are common. Here we introduce a novel mutational load hypothesis, which also considers the collective effect of mainly rare variants, utilising the Mut Pred Program.We apply this new methodology to investigate the possible role of mt DNA in two cardiovascular disease(CVD) phenotypes(hypertension and hyperglycaemia), within a two-population cohort(n = 363; mean age 45 ± 9 yrs). Very few studies have looked at African mt DNA variation in the context of complex disease, and none using complete sequence data in a well-phenotyped cohort. As such, our study will also extend our knowledge of African mt DNA variation, with complete sequences of Southern Africans being especially under-represented. The cohort showed prevalence rates for hypertension(58.6%) and prediabetes(44.8%). We could not identify a statistically significant role for mt DNA variation in association with hypertension or hyperglycaemia in our cohort. However, we are of the opinion that the method described will find wide application in the field, being especially useful for cohorts from multiple locations or with a variety of mt DNA lineages, where the traditional haplogroup association method has been particularly likely to generate spurious results in the context of association with common complex disease.  相似文献   

18.
As the largest carbon pool of the terrestrial ecosystem, forest plays a key role in sequestrating and reserving greenhouse gases. With the method of replacing space with time, the typical restoration ecosystems of herb (dominated by Deyeuxia scabrescens, P1), shrub (dominated by Salix paraqplesia, P2), broadleaf (dominated by Betula platyphylla, P3), mixed forest (dominated by Betula spp. and Abies faxoniana, P4), and climax (dominated by Abies faxoniana, P5) were selected to quantify the carbon stock and allocation in the subalpine coniferous forest in Western Sichuan (SCFS). The results indicated that the soil organism carbon (SOC) stock decreased with the depth of soil layer, and the SOC per layer and the total SOC increased largely with the vegetation restoration. The contribution of SOC to the carbon stock of ecosystems decreased with the vegetation restoration from 89.45% to 27.06%, while the quantity was from 94.00 to 223.00 t C hm?2. The carbon stock in ground cover increased with the vegetation restoration, and its contribution to the carbon stock of ecosystems was similar (3–4% of the total). Following the vegetation restoration, the plant carbon stock multiplied and reached to 430.86 ± 49.49 t C hm?2 at the climax phase. During the restoration, the carbon stock of different layers increased, and the contribution of belowground to the carbon stock of ecosystems decreased sharply. The carbon stock on ecosystem scale of the climax phase was 5.89 times that of the herb phase. Our results highlighted that the vegetation restoration in SCFS was a large carbon sink.  相似文献   

19.
When seedlings of two rice (Oryza sativa L.) cultivars Ratna and Jaya were raised under 100 and 500 μM cadmium nitrate in the medium, a high proline content was noted in Cd2+ stressed seedlings compared to controls. Seedlings grown under 500 μM Cd(NO3)2 maintained increased proline level compared to non-stressed seedlings. Kinetic properties of RNase extracted from control grown and Cd2+ stressed seedlings showed a marked alteration in Km due to Cd2+ treatment. The RNase isoforms were purified from 15-d-old rice seedlings with a total purification of 22.25 fold and 74.75 % yield using conventional biochemical techniques. Three RNase isoforms, namely I, II and III were eluted from DEAE-Sephacel column. The isoform RNase II had Km value of 3.2 mg(RNA) cm-3. The in vitro osmotic stress created by incorporation of PEG in the enzyme assay medium led to decreased affinity of enzyme towards its substrate with increase in Km. This loss in affinity was partially restored by the addition of 1 M proline in the assay medium, suggesting the possible protective role of proline on RNase under osmotic stress. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

20.
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