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1.
Am J Cancer Res ; 14(4): 1545-1560, 2024.
Article in English | MEDLINE | ID: mdl-38726264

ABSTRACT

Breast cancer represents the leading cancer type and leading cause of cancer-related death among women in the world. Triple-negative breast cancer (TNBC) is a subset of breast cancer with the poorest prognosis and still lacking of effective therapeutic options. We recently screened a natural product library and identified 3 new hit compounds with selective and prominent anti-TNBC activities on different subtype of TNBC cell lines. Interestingly, all of these 3 hit compounds belong to "cytoskeletal drugs" that target tubulin and microtubule function. Our data also showed that these hit compounds showed consistently effective on TNBC cells which are resistant to those currently used antimicrotubule agents such as Paclitaxel. RNA-Sequencing analyses revealed the anti-TNBC mechanisms of these hit compounds and identified a subset of new cellular factors commonly affected by hit compounds in different subtypes of TNBC cells. Among them, we demonstrated AHCYL1 and SPG21 as new microtubule-associated proteins, which were required for TNBC cell survival with clinical implication through tissue array analysis. Our studies provide new insights into the mechanisms of TNBC pathogenesis and offer promising therapeutic directions for this aggressive breast cancer.

2.
J Med Virol ; 96(3): e29534, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38501356

ABSTRACT

Human endogenous retrovirus sequences (HERVs) constitute up to 8% of the human genome, yet not all HERVs remain silent passengers within our genomes. Some HERVs, especially the HERV type K (HERV-K), have been found to be frequently transactivated in a variety of inflammatory diseases and human cancers. Np9, a 9-kDa HERV-K encoded protein, has been reported as an oncoprotein and found present in a variety of tumors and transformed cells. In the current study, we for the first time reported that ectopic expression of Np9 protein was able to induce DNA damage response from host cells especially through upregulation of γH2AX. Furthermore, we found that direct knockdown of Np9 by RNAi in Kaposi's Sarcoma-associated herpesvirus (KSHV) infected cells effectively reduced LANA expression, the viral major latent oncoprotein in vitro and in vivo, which may represent a novel strategy against virus-associated malignancies.


Subject(s)
Endogenous Retroviruses , Herpesvirus 8, Human , Neoplasms , Humans , Endogenous Retroviruses/genetics , Herpesvirus 8, Human/physiology , Oncogene Proteins/genetics , Oncogene Proteins/metabolism , DNA Repair
3.
J Hematol Oncol ; 16(1): 48, 2023 05 04.
Article in English | MEDLINE | ID: mdl-37143124

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of several human cancers, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), which preferentially arise in immunocompromised patients while lack of effective therapeutic options. Oncoproteins Myc and hypoxia-inducible factor-1α (HIF1α) have been found closely related to KSHV infection, replication and oncogenesis. However, the strategies of dual targeting these two oncoproteins have never been developed and tested for treatments of KSHV-related malignancies. In the current study, we report that treatment of echinomycin dramatically regresses cell growth both in vitro-cultured KSHV + tumor cells and in vivo KS or PEL xenograft mice models, through simultaneously inhibiting Myc and HIF1α expression. Echinomycin treatment also induces viral lytic gene expression whereas not increasing infectious virions production from KSHV + tumor cells. Our comparative transcriptomic analysis has identified a bunch of new Echinomycin-regulated, Myc- and HIF1α-related genes contributed to KSHV pathogenesis, including KDM4B and Tau, which are required for the survival of KSHV + tumor cells with functional validation. These data together reveal that dual targeting Myc and HIF1α such as using Echinomycin may represent a new and promising option for treatments of these virus-associated malignancies.


Subject(s)
Echinomycin , Herpesvirus 8, Human , Sarcoma, Kaposi , Humans , Animals , Mice , Herpesvirus 8, Human/genetics , Echinomycin/pharmacology , Echinomycin/therapeutic use , Virus Latency/genetics , Sarcoma, Kaposi/drug therapy , Sarcoma, Kaposi/metabolism , Cell Cycle , Jumonji Domain-Containing Histone Demethylases
4.
Viruses ; 15(4)2023 04 20.
Article in English | MEDLINE | ID: mdl-37112991

ABSTRACT

Although Kaposi's sarcoma-associated herpesvirus (KSHV) has been reported to cause several human cancers including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), the mechanisms of KSHV-induced tumorigenesis, especially virus-host interaction network, are still not completely understood, which therefore hinders the development of effective therapies. Histamine, together with its receptors, plays an important role in various allergic diseases by regulating different inflammation and immune responses. Our previous data showed that antagonists targeting histamine receptors effectively repressed KSHV lytic replication. In the current study, we determined that histamine treatment increased cell proliferation and anchorage-independent growth abilities of KSHV-infected cells. Furthermore, histamine treatment affected the expression of some inflammatory factors from KSHV-infected cells. For clinical relevance, several histamine receptors were highly expressed in AIDS-KS tissues when compared to normal skin tissues. We determined that histamine treatment promoted KSHV-infected lymphoma progression in immunocompromised mice models. Therefore, besides viral replication, our data indicate that the histamine and related signaling are also involved in other functions of KSHV pathogenesis and oncogenesis.


Subject(s)
Herpesvirus 8, Human , Sarcoma, Kaposi , Humans , Animals , Mice , Herpesvirus 8, Human/physiology , Histamine , Receptors, Histamine/therapeutic use , Carcinogenesis , Cell Transformation, Neoplastic
5.
Anticancer Drugs ; 34(7): 888-891, 2023 08 01.
Article in English | MEDLINE | ID: mdl-36730073

ABSTRACT

Anaplastic lymphoma kinase ( ALK ) rearrangements are one of the most common mutations in nonsmall cell lung cancer. Majority of the ALK rearrangements were sensitive to crizotinib, yet some rare fusion types may less benefit. The patient with LINC01923-ALK fusion was treated with crizotinib for 1 week and developed an adverse rash reaction. Replaced with second-line treatment with esatinib, the patient had a partial response in the primary site and achieved a complete response in the brain metastases. The patient was treated successfully with ensartinib leading to a progression-free survival of 6 months (and counting). This is the first report on one lung adenocarcinoma patient with a novel LINC01923-ALK fusion beneficial from ensartinib, which provides more knowledge for ALK fusion spectrum.


Subject(s)
Adenocarcinoma of Lung , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Crizotinib/therapeutic use , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Protein Kinase Inhibitors/therapeutic use , Adenocarcinoma of Lung/drug therapy , Adenocarcinoma of Lung/genetics
6.
PLoS Pathog ; 19(1): e1011089, 2023 01.
Article in English | MEDLINE | ID: mdl-36638143

ABSTRACT

Primary effusion lymphoma (PEL) caused by Kaposi sarcoma-associated herpesvirus (KSHV) is an aggressive malignancy with poor prognosis even under chemotherapy. Currently, there is no specific treatment for PEL therefore requiring new therapies. Both histone deacetylases (HDACs) and bromodomain-containing protein 4 (BRD4) have been found as therapeutic targets for PEL through inducing viral lytic reactivation. However, the strategy of dual targeting with one agent and potential synergistic effects have never been explored. In the current study, we first demonstrated the synergistic effect of concurrently targeting HDACs and BRD4 on KSHV reactivation by using SAHA or entinostat (HDACs inhibitors) and (+)-JQ1 (BRD4 inhibitor), which indicated dual blockage of HDACs/BRD4 is a viable therapeutic approach. We were then able to rationally design and synthesize a series of new small-molecule inhibitors targeting HDACs and BRD4 with a balanced activity profile by generating a hybrid of the key binding motifs between (+)-JQ1 and entinostat or SAHA. Upon two iterative screenings of optimized compounds, a pair of epimers, 009P1 and 009P2, were identified to better inhibit the growth of KSHV positive lymphomas compared to (+)-JQ1 or SAHA alone at low nanomolar concentrations, but not KSHV negative control cells or normal cells. Mechanistic studies of 009P1 and 009P2 demonstrated significantly enhanced viral reactivation, cell cycle arrest and apoptosis in KSHV+ lymphomas through dually targeting HDACs and BRD4 signaling activities. Importantly, in vivo preclinical studies showed that 009P1 and 009P2 dramatically suppressed KSHV+ lymphoma progression with oral bioavailability and minimal visible toxicity. These data together provide a novel strategy for the development of agents for inducing lytic activation-based therapies against these viruses-associated malignancies.


Subject(s)
Herpesvirus 8, Human , Lymphoma, Primary Effusion , Sarcoma, Kaposi , Humans , Transcription Factors/metabolism , Nuclear Proteins/metabolism , Histone Deacetylase Inhibitors/pharmacology , Herpesvirus 8, Human/physiology , Cell Line, Tumor , Cell Cycle Proteins/metabolism
7.
Front Cell Infect Microbiol ; 12: 1049624, 2022.
Article in English | MEDLINE | ID: mdl-36457850

ABSTRACT

Objective: Kaposi's Sarcoma-associated Herpesvirus (KSHV) is the etiologic agent of several human cancers, including Kaposi's sarcoma (KS) and Primary effusion lymphoma (PEL), which are usually seen in immunocompromised patients while lack of effective therapeutic options. Interleukin1 (IL1) family is a major mediator for inflammation response and has functional role in both innate and adaptive immunity. In contrast to the well-studied IL1 molecules, the activation and functional role of IL1 receptor/co-receptor and other related ligands, such as the IL1 receptor accessory protein (IL1RAP), in KSHV pathogenesis and tumorigenesis remain almost unknown. Methods: In the current study, a series of KSHV negative and positive primary or tumor cells, as well as AIDS-KS tumor samples from cohort HIV+ patients were used to compare and determine the activation status of IL1 signaling molecules, and their functional roles in KSHV pathogenesis. Results: We reported the high activation of multiple IL1 signaling molecules, including IL1, IL36, IL1R1, IL1RAP and IRAKs, during KSHV latent and lytic stages, as well as in clinical samples from patients with KSHV-related malignancies. Directly targeting these molecules especially IL1R1 and IL1RAP significantly impaired the survival and growth of KSHV+ tumor cells, as well as their colony formation on 3-D culture. Conclusion: Our data indicate the importance of IL1 signaling molecules in KSHV pathogenesis and tumorigenesis, which may represent attractive therapeutic targets against these virus-associated diseases.


Subject(s)
Herpesvirus 8, Human , Humans , Carcinogenesis , Cell Transformation, Neoplastic , Adaptive Immunity , Receptors, Interleukin-1
8.
Front Physiol ; 13: 981463, 2022.
Article in English | MEDLINE | ID: mdl-36072854

ABSTRACT

Owing to its significant contagion and mutation, the new crown pneumonia epidemic has caused more than 520 million infections worldwide and has brought irreversible effects on the society. Computed tomography (CT) images can clearly demonstrate lung lesions of patients. This study used deep learning techniques to assist doctors in the screening and quantitative analysis of this disease. Consequently, this study will help to improve the diagnostic efficiency and reduce the risk of infection. In this study, we propose a new method to improve U-Net for lesion segmentation in the chest CT images of COVID-19 patients. 750 annotated chest CT images of 150 patients diagnosed with COVID-19 were selected to classify, identify, and segment the background area, lung area, ground glass opacity, and lung parenchyma. First, to address the problem of a loss of lesion detail during down sampling, we replaced part of the convolution operation with atrous convolution in the encoder structure of the segmentation network and employed convolutional block attention module (CBAM) to enhance the weighting of important feature information. Second, the Swin Transformer structure is introduced in the last layer of the encoder to reduce the number of parameters and improve network performance. We used the CC-CCII lesion segmentation dataset for training and validation of the model effectiveness. The results of ablation experiments demonstrate that this method achieved significant performance gain, in which the mean pixel accuracy is 87.62%, mean intersection over union is 80.6%, and dice similarity coefficient is 88.27%. Further, we verified that this model achieved superior performance in comparison to other models. Thus, the method proposed herein can better assist doctors in evaluating and analyzing the condition of COVID-19 patients.

9.
J Med Virol ; 94(11): 5103-5111, 2022 11.
Article in English | MEDLINE | ID: mdl-35819034

ABSTRACT

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative pathogen for the coronavirus disease 2019 (COVID-19) pandemic, has greatly stressed our healthcare system. In addition to severe respiratory and systematic symptoms, several comorbidities increase the risk of fatal disease outcomes, including chronic viral infections. Increasing cases of lytic reactivation of human herpesviruses in COVID-19 patients and vaccinated people have been reported recently. SARS-CoV2 coinfection, COVID-19 treatments, and vaccination may aggravate those herpesvirus-associated diseases by reactivating the viruses in latently infected host cells. In this review, we summarize recent clinical findings and limited mechanistic studies regarding the relationship between SARS-CoV-2 and different human herpesviruses that suggest an ongoing potential threat to human health in the postpandemic era.


Subject(s)
COVID-19 , Herpesviridae , Humans , Pandemics , RNA, Viral , SARS-CoV-2
10.
Front Microbiol ; 13: 882520, 2022.
Article in English | MEDLINE | ID: mdl-35516440

ABSTRACT

Kaposi's Sarcoma (KS) caused by Kaposi's sarcoma-associated herpesvirus (KSHV) continues to be the most common AIDS-associated tumor. Involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. Numerous types of cancer are associated with the alterations of in components of the microbiome. However, little is known about how KSHV coinfection affects the oral microbiome in HIV+ patients, especially in a "pre-cancer" niche. Using 16S rRNA pyrosequencing, we found that oral shedding of KSHV correlated with altered oral microbiome signatures in HIV+ patients, including a reduction in the microbiota diversity, changing the relative composition of specific phyla and species, and regulating microbial functions. Furthermore, we found that Streptococcus sp., one of the most increased species in the oral cavity of HIV+/KSHV+ patients, induced KSHV lytic reactivation in primary oral cells. Together, these data indicate that oral shedding of KSHV may manipulate the oral microbiome to promote viral pathogenesis and tumorigenesis especially in immunocompromised patients.

11.
J Cell Mol Med ; 26(9): 2557-2565, 2022 05.
Article in English | MEDLINE | ID: mdl-35318805

ABSTRACT

Although small-cell lung cancer (SCLC) accounts for a small fraction of lung cancer cases (~15%), the prognosis of patients with SCLC is poor with an average overall survival period of a few months without treatment. Current treatments include standard chemotherapy, which has minimal efficacy and a newly developed immunotherapy that thus far, benefits a limited number of patients. In the current study, we screened a natural product library and identified 5 natural compounds, in particular tubercidin and lycorine HCl, that display prominent anti-SCLC activities in vitro and in vivo. Subsequent RNA-sequencing and functional validation assays revealed the anti-SCLC mechanisms of these new compounds, and further identified new cellular factors such as BCAT1 as a potential therapeutic target with clinical implication in SCLC patients. Taken together, our study provides promising new directions for fighting this aggressive lung cancer.


Subject(s)
Lung Neoplasms , Small Cell Lung Carcinoma , Amaryllidaceae Alkaloids , Humans , Immunotherapy , Phenanthridines , Small Cell Lung Carcinoma/drug therapy , Transaminases/therapeutic use , Tubercidin/therapeutic use
12.
Antimicrob Agents Chemother ; 66(3): e0239521, 2022 03 15.
Article in English | MEDLINE | ID: mdl-35041508

ABSTRACT

Recently, remdesivir and molnupiravir were approved for treating COVID-19 caused by SARS-CoV-2 infection. However, little is known about the impact of these drugs on other viruses preexisted in COVID-19 patients. Here we report that remdesivir but not molnupiravir induced lytic reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV), two major oncogenic herpesviruses. Remdesivir induced mature virion production from latently infected cells. Mechanistic studies showed that remdesivir induced KSHV and EBV reactivation by regulating several intracellular signaling pathways.


Subject(s)
COVID-19 Drug Treatment , Epstein-Barr Virus Infections , Herpesvirus 8, Human , Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Herpesvirus 4, Human/physiology , Humans , SARS-CoV-2 , Signal Transduction , Virus Activation
13.
Commun Biol ; 4(1): 682, 2021 06 03.
Article in English | MEDLINE | ID: mdl-34083759

ABSTRACT

An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of Coronavirus Disease-2019 (COVID-19), a respiratory disease, has infected almost one hundred million people since the end of 2019, killed over two million, and caused worldwide social and economic disruption. Because the mechanisms of SARS-CoV-2 infection of host cells and its pathogenesis remain largely unclear, there are currently no antiviral drugs with proven efficacy. Besides severe respiratory and systematic symptoms, several comorbidities increase risk of fatal disease outcome. Therefore, it is required to investigate the impacts of COVID-19 on pre-existing diseases of patients, such as cancer and other infectious diseases. In the current study, we report that SARS-CoV-2 encoded proteins and some currently used anti-COVID-19 drugs are able to induce lytic reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV), one of major human oncogenic viruses, through manipulation of intracellular signaling pathways. Our data indicate that those KSHV + patients especially in endemic areas exposure to COVID-19 or undergoing the treatment may have increased risks to develop virus-associated cancers, even after they have fully recovered from COVID-19.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/complications , Herpesvirus 8, Human/physiology , SARS-CoV-2/physiology , Sarcoma, Kaposi/etiology , Virus Activation , Azithromycin/pharmacology , Benzamidines/pharmacology , Cell Line , Guanidines/pharmacology , Herpesviridae Infections/chemically induced , Herpesviridae Infections/etiology , Herpesvirus 8, Human/drug effects , Humans , Oncogenic Viruses/drug effects , Oncogenic Viruses/physiology , SARS-CoV-2/drug effects , Sarcoma, Kaposi/chemically induced , Viral Proteins/metabolism , Virus Activation/drug effects , COVID-19 Drug Treatment
14.
J Cell Mol Med ; 25(6): 2795-2805, 2021 03.
Article in English | MEDLINE | ID: mdl-33539648

ABSTRACT

Although the Eukaryotic Translation Initiation Factor 4 Gamma 1 (EIF4G1) has been found overexpressed in a variety of cancers, its role in non-small cell lung cancers (NSCLC) pathogenesis especially in immunoregulatory functions, its clinical relevance and therapeutic potential remain largely unknown. By using cancer patients tissue assays, the results indicate that EIF4G1 expressional levels are much higher in NSCLC tissues than in adjacent or normal lung tissues, which are also associated with NSCLC patient survival. By using an RNA-Sequencing based pipeline, the data show that EIF4G1 has a significant association with immune checkpoint molecules such as PD-1/PD-L1 in NSCLC. EIF4G1 small-molecule inhibitors effectively repress NSCLC growth in cell culture and xenograft animal models. Protein array results identify the signature of proteins controlled by EIF4G1 in NSCLC cells, in which new candidates such as MUC1 and NRG1 are required for NSCLC survival and tumorigenesis with clinical relevance. Taken together, these results have for the first time demonstrated the immunoregulatory functions, clinical relevance and therapeutic potential of the EIF4G1 network in NSCLC, which may represent a promising and novel target to improve lung cancer treatment.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Eukaryotic Initiation Factor-4G/genetics , Gene Expression Regulation, Neoplastic , Gene Regulatory Networks , Lung Neoplasms/genetics , Animals , Biomarkers, Tumor , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/mortality , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation , Cell Survival , Disease Models, Animal , Disease Progression , Eukaryotic Initiation Factor-4G/metabolism , Humans , Immune Checkpoint Proteins/genetics , Immune Checkpoint Proteins/metabolism , Immunohistochemistry , Lung Neoplasms/metabolism , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Mice , Xenograft Model Antitumor Assays
15.
J Med Virol ; 93(6): 4028-4032, 2021 06.
Article in English | MEDLINE | ID: mdl-32648938

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) causes several human cancers, including Kaposi's sarcoma (KS) and primary effusion lymphoma, which are mostly seen in immunocompromised patients, such as human immunodefeciency virus (HIV)+ individuals. Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb), remains one of the deadliest infectious diseases in the world. The risk of developing TB is dramatically higher in people living with HIV than among those without HIV infection. Case reports link cutaneous or pulmonary KS in HIV+ patients with mycobacterial co-infections, however, impacts of Mtb infection or its products on KSHV-infected cells are not known. We report here that ESAT-6, a secreted Mtb virulence factor, induces viral reactivation from KSHV-infected cells. KSHV-infected pulmonary endothelial cells were resistant to ESAT-6 induced inhibition of cell growth. Our data demonstrate that Mtb virulence factors influence the biology of KSHV-infected cells, highlighting the need to study the interactions between these two pathogens commonly found in people living with HIV.


Subject(s)
Antigens, Bacterial/genetics , Bacterial Proteins/genetics , Herpesvirus 8, Human/physiology , Mycobacterium tuberculosis/genetics , Sarcoma, Kaposi/virology , Virus Activation , Antigens, Bacterial/pharmacology , Bacterial Proteins/pharmacology , Cell Line, Tumor , Cells, Cultured , Endothelial Cells/drug effects , Endothelial Cells/microbiology , Endothelial Cells/virology , Gene Expression Regulation, Viral , Humans , Lung/cytology , Mycobacterium tuberculosis/pathogenicity , Virulence Factors , Virus Replication
16.
Front Cell Infect Microbiol ; 10: 587929, 2020.
Article in English | MEDLINE | ID: mdl-33194830

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) represents the etiological agent for several human malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD), which are mostly seen in immunocompromised patients. In fact, KSHV has developed many strategies to hijack host immune response, including the regulation of inflammatory cytokine production. Interleukin-1 (IL-1) family represents a major mediator for inflammation and plays an important role in both innate and adaptive immunity. Furthermore, a broadening list of diseases has revealed the pathologic role of IL-1 mediated inflammation. In the current mini-review, we have summarized recent findings about how this oncogenic virus is able to manipulate the activities of IL-1 signaling pathway to facilitate disease progression. We also discuss the therapeutic potential of IL-1 blockade against KSHV-related diseases and several unsolved questions in this interesting field.


Subject(s)
Herpesvirus 8, Human , Sarcoma, Kaposi , Humans , Interleukin-1 , Signal Transduction
17.
bioRxiv ; 2020 Oct 02.
Article in English | MEDLINE | ID: mdl-33024968

ABSTRACT

An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of Coronavirus Disease-2019 (COVID-19), a respiratory disease, has infected over 34,000,000 people since the end of 2019, killed over 1,000,000, and caused worldwide social and economic disruption. Due to the mechanisms of SARS-CoV-2 infection to host cells and its pathogenesis remain largely unclear, there are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Besides severe respiratory and systematic symptoms, several comorbidities may also increase risk of fatal disease outcome. Therefore, it is required to investigate the impacts of COVID-19 on pre-existing diseases of patients, such as cancer and other infectious diseases. In the current study, we have reported that SARS-CoV-2 encoded proteins and some anti-COVID-19 drugs currently used are able to induce lytic reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV), one of major human oncogenic viruses through manipulation of intracellular signaling pathways. Our data indicate that those KSHV+ patients especially in endemic areas exposure to COVID-19 or undergoing the treatment may have increased risks to develop virus-associated cancers, even after they have fully recovered from COVID-19.

18.
Sci Total Environ ; 748: 141318, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-32814291

ABSTRACT

Numerous studies have investigated the impact of nitrogen (N) addition on ecosystem carbon (C) storage and cycling. However, how N addition regulates the dynamics of different soil organic carbon (SOC) fractions and the underlying microbial mechanisms remain unclear. In this study, we assessed microbial controls (through biomass, residues and enzymes) of different SOC fractions (particulate organic carbon, POC and mineral-associated organic carbon, MAOC) in response to six years of N addition (50 kg N ha-1 yr-1) in two temperate forests (Betula platyphylla vs. Quercus wutaishanica) in Northern China. Plant inputs (root biomass and leaf litterfall) and soil chemistry (pH, extractable inorganic N, and exchangeable cations) were unaltered by N addition in both forests. In the Q. wutaishanica forest, microbial biomass, residues, and enzymes were not sensitive to N addition, which may explain the lack of response in SOC and two fractions (POC and MAOC). However, in the B. platyphylla forest, although microbial biomass and enzymes as well as SOC and POC did not significantly change after N addition, both microbial residues (amino sugars) and MAOC significantly increased after N addition. Moreover, there was a strong positive correlation between microbial residues and MAOC pool within or across the two forests. Collectively, these results suggest that the dynamics of microbial residues play a crucial role in controlling the response of mineral-associated SOC to N addition in these two forests. Separating bulk soil into distinct functional pools and considering microbial residues should help reveal the nuanced response of soil C dynamics under N addition.


Subject(s)
Carbon , Soil , Biomass , Carbon/analysis , China , Ecosystem , Forests , Minerals , Nitrogen/analysis , Soil Microbiology
19.
J Cancer ; 11(16): 4683-4691, 2020.
Article in English | MEDLINE | ID: mdl-32626514

ABSTRACT

As a highly aggressive pediatric brainstem tumor, diffuse intrinsic pontine glioma (DIPG) accounts for 10% to 20% of childhood brain tumors. The survival rate for DIPG remains very low, with a median survival time as less than one year even under radiotherapy, the current standard treatment. Moreover, over than 250 clinical trials have failed when trying to improve the survival compared to radiotherapy. The sphingolipid metabolism and related signaling pathways have been found closely related to cancer cell survival; however, the sphingolipid metabolism targeted therapies have never been investigated in DIPG. In the current study, the anti-DIPG activity of ABC294640, the only first-in-class orally available Sphingosine kinase (SphK) inhibitor was explored. Treatment with ABC294640 significantly repressed DIPG cell growth by inducing intracellular pro-apoptotic ceramides production and cell apoptosis. We also profiled ABC294640-induced changes in gene expression within DIPG cells and identified many new genes tightly controlled by sphingolipid metabolism, such as IFITM1 and KAL1. These genes are required for DIPG cell survival and display clinical relevance in DIPG patients' samples. Together, our findings in this study indicate that targeting sphingolipid metabolism may represent a promising strategy to improve DIPG treatment.

20.
Blood ; 136(19): 2175-2187, 2020 11 05.
Article in English | MEDLINE | ID: mdl-32518949

ABSTRACT

Primary effusion lymphoma (PEL) is an aggressive malignancy with poor prognosis even under chemotherapy. Kaposi sarcoma-associated herpesvirus (KSHV), one of the human oncogenic viruses, is the principal causative agent. Currently, there is no specific treatment for PEL; therefore, developing new therapies is of great importance. Sphingolipid metabolism plays an important role in determining the fate of tumor cells. Our previous studies have demonstrated that there is a correlation between sphingolipid metabolism and KSHV+ tumor cell survival. To further develop sphingolipid metabolism-targeted therapy, after screening a series of newly synthesized ceramide analogs, here, we have identified compounds with effective anti-PEL activity. These compounds induce significant PEL apoptosis, cell-cycle arrest, and intracellular ceramide production through regulation of ceramide synthesizing or ceramide metabolizing enzymes and dramatically suppress tumor progression without visible toxicity in vivo. These new compounds also increase viral lytic gene expression in PEL cells. Our comparative transcriptomic analysis revealed their mechanisms of action for inducing PEL cell death and identified a subset of novel cellular genes, including AURKA and CDCA3, controlled by sphingolipid metabolism, and required for PEL survival with functional validation. These data provide the framework for the development of promising sphingolipid-based therapies against this virus-associated malignancy.


Subject(s)
Aurora Kinase A/metabolism , Ceramides/pharmacology , Herpesvirus 8, Human/pathogenicity , Lymphoma, Primary Effusion/drug therapy , Sarcoma, Kaposi/complications , Sphingolipids/pharmacology , Animals , Apoptosis , Aurora Kinase A/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Survival , Ceramides/chemistry , Female , Gene Expression Profiling , Humans , Lymphoma, Primary Effusion/etiology , Lymphoma, Primary Effusion/metabolism , Lymphoma, Primary Effusion/pathology , Mice , Mice, Inbred NOD , Mice, SCID , Sarcoma, Kaposi/virology , Tumor Cells, Cultured , Virus Replication , Xenograft Model Antitumor Assays
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