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1.
Transl Oncol ; 41: 101879, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38262110

RESUMO

Fluctuations in the number of regulatory molecules and differences in timings of molecular events can generate variation in gene expression among genetically identical cells in the same environmental condition. This variation, termed as expression noise, can create differences in metabolic state and cellular functions, leading to phenotypic heterogeneity. Expression noise and phenotypic heterogeneity have been recognized as important contributors to intra-tumor heterogeneity, and have been associated with cancer growth, progression, and therapy resistance. However, how expression noise changes with cancer progression in actual cancer patients has remained poorly explored. Such an analysis, through identification of genes with increasing expression noise, can provide valuable insights into generation of intra-tumor heterogeneity, and could have important implications for understanding immune-suppression, drug tolerance and therapy resistance. In this work, we performed a genome-wide identification of changes in gene expression noise with cancer progression using single-cell RNA-seq data of lung adenocarcinoma patients at different stages of cancer. We identified 37 genes in epithelial cells that showed an increasing noise trend with cancer progression, many of which were also associated with cancer growth, EMT and therapy resistance. We found that expression of several of these genes was positively associated with expression of mitochondrial genes, suggesting an important role of mitochondria in generation of heterogeneity. In addition, we uncovered substantial differences in sample-specific noise profiles which could have implications for personalized prognosis and treatment.

3.
Oncogene ; 42(37): 2725-2736, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37550562

RESUMO

PG545 (Pixatimod) is a highly sulfated small molecule known for its ability to inhibit heparanase and disrupt signaling mediated by heparan-binding-growth factors (HB-GF). Previous studies indicated that PG545 inhibits growth factor-mediated signaling in ovarian cancer (OC) to enhance response to chemotherapy. Here we investigated the previously unidentified mechanisms by which PG545 induces DNA damage in OC cells and found that PG545 induces DNA single- and double-strand breaks, reduces RAD51 expression in an autophagy-dependent manner and inhibits homologous recombination repair (HRR). These changes accompanied the ability of PG545 to inhibit endocytosis of the heparan-sulfate proteoglycan interacting DNA repair protein, DEK, leading to DEK sequestration in the tumor microenvironment (TME) and loss of nuclear DEK needed for HRR. As a result, PG545 synergized with poly (ADP-ribose) polymerase inhibitors (PARPis) in OC cell lines in vitro and in 55% of primary cultures of patient-derived ascites samples ex vivo. Moreover, PG545/PARPi synergy was observed in OC cells exhibiting either de novo or acquired resistance to PARPi monotherapy. PG545 in combination with rucaparib also generated increased DNA damage, increased antitumor effects and increased survival of mice bearing HRR proficient OVCAR5 xenografts compared to monotherapy treatment in vivo. Synergistic antitumor activity of the PG545/rucaparib combination was likewise observed in an immunocompetent syngeneic ID8F3 OC model. Collectively, these results suggest that targeting DEK-HSPG interactions in the TME through the use of PG545 may be a novel method of inhibiting DNA repair and sensitizing cells to PARPis.


Assuntos
Neoplasias Ovarianas , Inibidores de Poli(ADP-Ribose) Polimerases , Saponinas , Animais , Feminino , Humanos , Camundongos , Inibidores da Angiogênese/farmacologia , Linhagem Celular Tumoral , Reparo do DNA , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Microambiente Tumoral , Saponinas/farmacologia , Saponinas/uso terapêutico
4.
J Med Virol ; 95(5): e28796, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37218551

RESUMO

Host proteases trypsin and trypsin-like proteases have been reported to facilitate the entry of coronavirus SARS-CoV-2 in its host cells. These protease enzymes cleave the viral surface glycoprotein, spike, leading to successful cell surface receptor attachment, fusion and entry of the virus in its host cell. The spike protein has protease cleavage sites between the two domains S1 and S2. Since the cleavage site is recognized by the host proteases, it can be a potential antiviral therapeutic target. Trypsin-like proteases play an important role in virus infectivity and the property of spike protein cleavage by trypsin and trypsin-like proteases can be used to design assays for screening of antiviral candidates against spike protein cleavage. Here, we have documented the development of a proof-of-concept assay system for screening drugs against trypsin/trypsin-like proteases that cleave spike protein between its S1 and S2 domains. The assay system developed uses a fusion substrate protein containing a NanoLuc luciferase reporter protein, the protease cleavage site between S1 and S2 domains of SARS-CoV-2 spike protein and a cellulose binding domain. The substrate protein can be immobilized on cellulose via the cellulose binding domain of the substrate. When trypsin and trypsin-like proteases cleave the substrate, the cellulose binding domain remain bound to the cellulose and the reporter protein is dislodged. Reporter assay using the released reporter protein is the read out of the protease activity. We have demonstrated the proof-of-concept using multiple proteases like trypsin, TMPRSS2, furin, cathepsin B, human airway trypsin and cathepsin L. A significant increment in fold change was observed with increasing enzyme concentration and incubation time. Introduction of increasing amounts of enzyme inhibitors in the reaction reduced the luminescent signal, thus validating the assay. Furthermore, we used SDS-PAGE and immunoblot analyses to study the cleavage band pattern and re-confirm the cleavage for enzymes tested in the assay. Taken together, we have tested an in-vitro assay system using the proposed substrate for screening drugs against trypsin like protease-based cleavage of SARS-CoV-2 spike glycoprotein. The assay system can also be potentially used for antiviral drug screening against any other enzyme that might cleave the used cleavage site.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Humanos , Glicoproteína da Espícula de Coronavírus/metabolismo , Tripsina , Internalização do Vírus , SARS-CoV-2/metabolismo , Peptídeo Hidrolases
5.
Pharmaceuticals (Basel) ; 16(4)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37111346

RESUMO

Multiple myeloma is a malignancy of immunoglobulin-secreting plasma cells that is now often treated in the newly diagnosed and relapsed and/or refractory settings with monoclonal antibodies targeting lineage-specific markers used either alone or in rationally designed combination regimens. Among these are the anti-CD38 antibodies daratumumab and isatuximab, and the anti-Signaling lymphocytic activation molecule family member 7 antibody elotuzumab, all of which are used in their unconjugated formats. Single-chain variable fragments from antibodies also form a key element of the chimeric antigen receptors (CARs) in the B-cell maturation antigen (BCMA)-targeted CAR T-cell products idecabtagene vicleucel and ciltacabtagene autoleucel, which are approved in the advanced setting. Most recently, the bispecific anti-BCMA and T-cell-engaging antibody teclistamab has become available, again for patients with relapsed/refractory disease. Another format into which antibodies can be converted to exert anti-tumor efficacy is as antibody-drug conjugates (ADCs), and belantamab mafodotin, which also targets BCMA, represented the first such agent that gained a foothold in myeloma. Negative results from a recent Phase III study have prompted the initiation of a process for withdrawal of its marketing authorization. However, belantamab remains a drug with some promise, and many other ADCs targeting either BCMA or other plasma cell surface markers are in development and showing potential. This contribution will provide an overview of some of the current data supporting the possibility that ADCs will remain a part of our chemotherapeutic armamentarium against myeloma moving forward, and also highlight areas for future development.

7.
Oncogene ; 41(33): 4003-4017, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35804016

RESUMO

PFKFB3 (6-phosphofructo-2-kinase) is the rate-limiting enzyme of glycolysis and is overexpressed in several human cancers that are associated with poor prognosis. High PFKFB3 expression in cancer stem cells promotes glycolysis and survival in the tumor microenvironment. Inhibition of PFKFB3 by the glycolytic inhibitor PFK158 and by shRNA stable knockdown in small cell lung carcinoma (SCLC) cell lines inhibited glycolysis, proliferation, spheroid formation, and the expression of cancer stem cell markers CD133, Aldh1, CD44, Sox2, and ABCG2. These factors are also associated with chemotherapy resistance. We found that PFK158 treatment and PFKFB3 knockdown enhanced the ABCG2-interacting drugs doxorubicin, etoposide, and 5-fluorouracil in reducing cell viability under conditions of enriched cancer stem cells (CSC). Additionally, PFKFB3 inhibition attenuated the invasion/migration of SCLC cells by downregulating YAP/TAZ signaling while increasing pLATS1 via activation of pMST1 and NF2 and by reducing the mesenchymal protein expression. PFKFB3 knockdown and PFK158 treatment in a H1048 SCLC cancer stem cell-enriched mouse xenograft model showed significant reduction in tumor growth and weight with reduced expression of cancer stem cell markers, ABCG2, and YAP/TAZ. Our findings identify that PFKFB3 is a novel target to regulate cancer stem cells and its associated therapeutic resistance markers YAP/TAZ and ABCG2 in SCLC models.


Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Animais , Linhagem Celular Tumoral , Proliferação de Células , Glicólise , Via de Sinalização Hippo , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Fosfofrutoquinase-2/metabolismo , Piridinas , Quinolinas , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/genética , Microambiente Tumoral
8.
NAR Cancer ; 4(3): zcac022, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35875052

RESUMO

A problematic feature of many human cancers is a lack of understanding of mechanisms controlling organ-specific patterns of metastasis, despite recent progress in identifying many mutations and transcriptional programs shown to confer this potential. To address this gap, we developed a methodology that enables different aspects of the metastatic process to be comprehensively characterized at a clonal resolution. Our approach exploits the application of a computational pipeline to analyze and visualize clonal data obtained from transplant experiments in which a cellular DNA barcoding strategy is used to distinguish the separate clonal contributions of two or more competing cell populations. To illustrate the power of this methodology, we demonstrate its ability to discriminate the metastatic behavior in immunodeficient mice of a well-established human metastatic cancer cell line and its co-transplanted LRRC15 knockdown derivative. We also show how the use of machine learning to quantify clone-initiating cell (CIC) numbers and their subsequent metastatic progeny generated in different sites can reveal previously unknown relationships between different cellular genotypes and their initial sites of implantation with their subsequent respective dissemination patterns. These findings underscore the potential of such combined genomic and computational methodologies to identify new clonally-relevant drivers of site-specific patterns of metastasis.

9.
FEBS Open Bio ; 12(9): 1657-1676, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35686673

RESUMO

Ovarian cancer ranks fifth in terms of cancer mortality in women due to lack of early diagnosis and poor clinical management. Characteristics like high cellular proliferation, EMT and metabolic alterations contribute to oncogenicity. Cancer, being a "metabolic disorder," is governed by various key regulatory factors like metabolic enzymes, oncogenes, and tumor suppressors. Sirtuins (SIRT1-SIRT7) belong to the group of NAD+ deacetylase and ADP-ribosylation enzymes that function as NAD+ sensors and metabolic regulators. Among sirtuin orthologs, SIRT6 emerges as an important oncogenic player, although its possible mechanistic involvement in ovarian cancer advancement is still elusive. Our data indicated a higher expression of SIRT6 in ovarian cancer tissues compared with the non-malignant ovarian tissue. Further, we observed that overexpression of SIRT6 enhances glycolysis and oxidative phosphorylation in ovarian cancer cells. The energy derived from these processes facilitates migration and invasion through invadopodia formation by reorganization of actin fibers. Mechanistically, SIRT6 has been shown to promote ERK1/2-driven activatory phosphorylation of DRP1 at serine-616, which has an obligatory role in inducing mitochondrial fission. These fragmented mitochondria facilitate cell movement important for metastases. siRNA-mediated downregulation of SIRT6 was found to decrease cellular invasion through compromised mitochondrial fragmentation and subsequent reduction in stress fiber formation in ovarian cancer cells. Thus, the present report establishes the impact of SIRT6 in the regulation of morphological and functional aspects of mitochondria that modulates invasion in ovarian cancer cells.


Assuntos
Dinâmica Mitocondrial , Neoplasias Ovarianas , Sirtuínas , Feminino , Glicólise , Humanos , NAD/metabolismo , Invasividade Neoplásica , Neoplasias Ovarianas/patologia , Sirtuínas/metabolismo
10.
Cancer Res ; 82(9): 1675-1681, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35260879

RESUMO

Abundant fibrotic stroma is a typical feature of most solid tumors, and stromal activation promotes oncogenesis, therapy resistance, and metastatic dissemination of cancer cells. Therefore, targeting the tumor stroma in combination with standard-of-care therapies has become a promising therapeutic strategy in recent years. The leucine-rich repeat-containing protein 15 (LRRC15) is involved in cell-cell and cell-matrix interactions and came into focus as a promising anticancer target owing to its overexpression in mesenchymal-derived tumors such as sarcoma, glioblastoma, and melanoma and in cancer-associated fibroblasts in the microenvironment of breast, head and neck, lung, and pancreatic tumors. Effective targeting of LRRC15 using specific antibody-drug conjugates (ADC) has the potential to improve the outcome of patients with LRRC15-positive (LRRC15+) cancers of mesenchymal origin or stromal desmoplasia. Moreover, LRRC15 expression may serve as a predictive biomarker that could be utilized in the preclinical assessment of cancer patients to support personalized clinical outcomes. This review focuses on the role of LRRC15 in cancer, including clinical trials involving LRRC15-targeted therapies, such as the ABBV-085 ADC for patients with LRRC15+ tumors. This review spans perceived knowledge gaps and highlights the clinical avenues that need to be explored to provide better therapeutic outcomes in patients.


Assuntos
Fibroblastos Associados a Câncer , Glioblastoma , Imunoconjugados , Sarcoma , Fibroblastos Associados a Câncer/metabolismo , Glioblastoma/metabolismo , Humanos , Imunoconjugados/farmacologia , Proteínas de Membrana/metabolismo , Sarcoma/tratamento farmacológico , Microambiente Tumoral
11.
Cancer Res ; 82(6): 1038-1054, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654724

RESUMO

Dissemination of ovarian cancer cells can lead to inoperable metastatic lesions in the bowel and omentum that cause patient death. Here we show that LRRC15, a type-I 15-leucine-rich repeat-containing membrane protein, highly overexpressed in ovarian cancer bowel metastases compared with matched primary tumors and acts as a potent promoter of omental metastasis. Complementary models of ovarian cancer demonstrated that LRRC15 expression leads to inhibition of anoikis-induced cell death and promotes adhesion and invasion through matrices that mimic omentum. Mechanistically, LRRC15 interacted with ß1-integrin to stimulate activation of focal adhesion kinase (FAK) signaling. As a therapeutic proof of concept, targeting LRRC15 with the specific antibody-drug conjugate ABBV-085 in both early and late metastatic ovarian cancer cell line xenograft models prevented metastatic dissemination, and these results were corroborated in metastatic patient-derived ovarian cancer xenograft models. Furthermore, treatment of 3D-spheroid cultures of LRRC15-positive patient-derived ascites with ABBV-085 reduced cell viability. Overall, these data uncover a role for LRRC15 in promoting ovarian cancer metastasis and suggest a novel and promising therapy to target ovarian cancer metastases.Significance: This study identifies that LRRC15 activates ß1-integrin/FAK signaling to promote ovarian cancer metastasis and shows that the LRRC15-targeted antibody-drug conjugate ABBV-085 suppresses ovarian cancer metastasis in preclinical models.


Assuntos
Imunoconjugados , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Adesão Celular , Linhagem Celular Tumoral , Feminino , Humanos , Imunoconjugados/farmacologia , Integrinas , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia
12.
Cancers (Basel) ; 13(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34572872

RESUMO

A considerable subset of gynecologic cancer patients experience disease recurrence or acquired resistance, which contributes to high mortality rates in ovarian cancer (OC). Our prior studies showed that quinacrine (QC), an antimalarial drug, enhanced chemotherapy sensitivity in treatment-refractory OC cells, including artificially generated chemoresistant and high-grade serous OC cells. In this study, we investigated QC-induced transcriptomic changes to uncover its cytotoxic mechanisms of action. Isogenic pairs of OC cells generated to be chemoresistant and their chemosensitive counterparts were treated with QC followed by RNA-seq analysis. Validation of selected expression results and database comparison analyses indicated the ribosomal biogenesis (RBG) pathway is inhibited by QC. RBG is commonly upregulated in cancer cells and is emerging as a drug target. We found that QC attenuates the in vitro and in vivo expression of nucleostemin (NS/GNL3), a nucleolar RBG and DNA repair protein, and the RPA194 catalytic subunit of Pol I that results in RBG inhibition and nucleolar stress. QC promotes the redistribution of fibrillarin in the form of extranuclear foci and nucleolar caps, an indicator of nucleolar stress conditions. In addition, we found that QC-induced downregulation of NS disrupted homologous recombination repair both by reducing NS protein levels and PARylation resulting in reduced RAD51 recruitment to DNA damage. Our data suggest that QC inhibits RBG and this inhibition promotes DNA damage by directly downregulating the NS-RAD51 interaction. Additionally, QC showed strong synergy with PARP inhibitors in OC cells. Overall, we found that QC downregulates the RBG pathway, induces nucleolar stress, supports the increase of DNA damage, and sensitizes cells to PARP inhibition, which supports new therapeutic stratagems for treatment-refractory OC. Our work offers support for targeting RBG in OC and determines NS to be a novel target for QC.

13.
Biochem Biophys Res Commun ; 571: 26-31, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34303192

RESUMO

The pandemic of SARS-CoV-2 has necessitated expedited research efforts towards finding potential antiviral targets and drug development measures. While new drug discovery is time consuming, drug repurposing has been a promising area for elaborate virtual screening and identification of existing FDA approved drugs that could possibly be used for targeting against functions of various proteins of SARS-CoV-2 virus. RNA dependent RNA polymerase (RdRp) is an important enzyme for the virus that mediates replication of the viral RNA. Inhibition of RdRp could inhibit viral RNA replication and thus new virus particle production. Here, we screened non-nucleoside antivirals and found three out of them to be strongest in binding to RdRp out of which two retained binding even using molecular dynamic simulations. We propose these two drugs as potential RdRp inhibitors which need further in-depth testing.


Assuntos
Antivirais/farmacologia , Tratamento Farmacológico da COVID-19 , RNA-Polimerase RNA-Dependente de Coronavírus/antagonistas & inibidores , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia , Amidas/farmacologia , Antivirais/química , Benzimidazóis/farmacologia , COVID-19/virologia , Carbamatos/farmacologia , Domínio Catalítico , Simulação por Computador , RNA-Polimerase RNA-Dependente de Coronavírus/química , Ciclopropanos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Fluorenos/farmacologia , Humanos , Lactamas Macrocíclicas/farmacologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Pandemias , Prolina/análogos & derivados , Prolina/farmacologia , Conformação Proteica , Quinoxalinas/farmacologia , Sulfonamidas/farmacologia
14.
J Exp Clin Cancer Res ; 40(1): 182, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082797

RESUMO

BACKGROUND: Aberrant lipogenicity and deregulated autophagy are common in most advanced human cancer and therapeutic strategies to exploit these pathways are currently under consideration. Group III Phospholipase A2 (sPLA2-III/PLA2G3), an atypical secretory PLA2, is recognized as a regulator of lipid metabolism associated with oncogenesis. Though recent studies reveal that high PLA2G3 expression significantly correlates with poor prognosis in several cancers, however, role of PLA2G3 in ovarian cancer (OC) pathogenesis is still undetermined. METHODS: CRISPR-Cas9 and shRNA mediated knockout and knockdown of PLA2G3 in OC cells were used to evaluate lipid droplet (LD) biogenesis by confocal and Transmission electron microscopy analysis, and the cell viability and sensitization of the cells to platinum-mediated cytotoxicity by MTT assay. Regulation of primary ciliation by PLA2G3 downregulation both genetically and by metabolic inhibitor PFK-158 induced autophagy was assessed by immunofluorescence-based confocal analysis and immunoblot. Transient transfection with GFP-RFP-LC3B and confocal analysis was used to assess the autophagic flux in OC cells. PLA2G3 knockout OVCAR5 xenograft in combination with carboplatin on tumor growth and metastasis was assessed in vivo. Efficacy of PFK158 alone and with platinum drugs was determined in patient-derived primary ascites cultures expressing PLA2G3 by MTT assay and immunoblot analysis. RESULTS: Downregulation of PLA2G3 in OVCAR8 and 5 cells inhibited LD biogenesis, decreased growth and sensitized cells to platinum drug mediated cytotoxicity in vitro and in in vivo OVCAR5 xenograft. PLA2G3 knockdown in HeyA8MDR-resistant cells showed sensitivity to carboplatin treatment. We found that both PFK158 inhibitor-mediated and genetic downregulation of PLA2G3 resulted in increased number of percent ciliated cells and inhibited cancer progression. Mechanistically, we found that PFK158-induced autophagy targeted PLA2G3 to restore primary cilia in OC cells. Of clinical relevance, PFK158 also induces percent ciliated cells in human-derived primary ascites cells and reduces cell viability with sensitization to chemotherapy. CONCLUSIONS: Taken together, our study for the first time emphasizes the role of PLA2G3 in regulating the OC metastasis. This study further suggests the therapeutic potential of targeting phospholipases and/or restoration of PC for future OC treatment and the critical role of PLA2G3 in regulating ciliary function by coordinating interface between lipogenesis and metastasis.


Assuntos
Proliferação de Células/efeitos dos fármacos , Fosfolipases A2 do Grupo III/genética , Lipogênese/efeitos dos fármacos , Neoplasias Ovarianas/tratamento farmacológico , Animais , Autofagia/efeitos dos fármacos , Sistemas CRISPR-Cas/genética , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Xenoenxertos , Humanos , Gotículas Lipídicas/efeitos dos fármacos , Camundongos , Microscopia Eletrônica de Transmissão , Metástase Neoplásica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Platina/farmacologia , Piridinas/farmacologia , Quinolinas/farmacologia
15.
Cancers (Basel) ; 13(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919392

RESUMO

We previously reported that the antimalarial compound quinacrine (QC) induces autophagy in ovarian cancer cells. In the current study, we uncovered that QC significantly upregulates cathepsin L (CTSL) but not cathepsin B and D levels, implicating the specific role of CTSL in promoting QC-induced autophagic flux and apoptotic cell death in OC cells. Using a Magic Red® cathepsin L activity assay and LysoTracker red, we discerned that QC-induced CTSL activation promotes lysosomal membrane permeability (LMP) resulting in the release of active CTSL into the cytosol to promote apoptotic cell death. We found that QC-induced LMP and CTSL activation promotes Bid cleavage, mitochondrial outer membrane permeabilization (MOMP), and mitochondrial cytochrome-c release. Genetic (shRNA) and pharmacological (Z-FY(tBU)-DMK) inhibition of CTSL markedly reduces QC-induced autophagy, LMP, MOMP, apoptosis, and cell death; whereas induced overexpression of CTSL in ovarian cancer cell lines has an opposite effect. Using recombinant CTSL, we identified p62/SQSTM1 as a novel substrate of CTSL, suggesting that CTSL promotes QC-induced autophagic flux. CTSL activation is specific to QC-induced autophagy since no CTSL activation is seen in ATG5 knockout cells or with the anti-malarial autophagy-inhibiting drug chloroquine. Importantly, we showed that upregulation of CTSL in QC-treated HeyA8MDR xenografts corresponds with attenuation of p62, upregulation of LC3BII, cytochrome-c, tBid, cleaved PARP, and caspase3. Taken together, the data suggest that QC-induced autophagy and CTSL upregulation promote a positive feedback loop leading to excessive autophagic flux, LMP, and MOMP to promote QC-induced cell death in ovarian cancer cells.

16.
Oncogene ; 40(8): 1409-1424, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33420377

RESUMO

The advanced or recurrent endometrial cancer (EC) has a poor prognosis because of chemoresistance. 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a glycolytic enzyme, is overexpressed in a variety of human cancers and plays important roles in promoting tumor cell growth. Here, we showed that high expression of PFKFB3 in EC cell lines is associated with chemoresistance. Pharmacological inhibition of PFKFB3 with PFK158 and or genetic downregulation of PFKFB3 dramatically suppressed cell proliferation and enhanced the sensitivity of EC cells to carboplatin (CBPt) and cisplatin (Cis). Moreover, PFKFB3 inhibition resulted in reduced glucose uptake, ATP production, and lactate release. Notably, we found that PFK158 with CBPt or Cis exerted strong synergistic antitumor activity in chemoresistant EC cell lines, HEC-1B and ARK-2 cells. We also found that the combination of PFK158 and CBPt/Cis induced apoptosis- and autophagy-mediated cell death through inhibition of the Akt/mTOR signaling pathway. Mechanistically, we found that PFK158 downregulated the CBPt/Cis-induced upregulation of RAD51 expression and enhanced CBPt/Cis-induced DNA damage as demonstrated by an increase in γ-H2AX levels in HEC-1B and ARK-2 cells, potentially revealing a means to enhance PFK158-induced chemosensitivity. More importantly, PFK158 treatment, either as monotherapy or in combination with CBPt, led to a marked reduction in tumor growth in two chemoresistant EC mouse xenograft models. These data suggest that PFKFB3 inhibition alone or in combination with standard chemotherapy may be used as a novel therapeutic strategy for improved therapeutic efficacy and outcomes of advanced and recurrent EC patients.


Assuntos
Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias do Endométrio/tratamento farmacológico , Fosfofrutoquinase-2/genética , Apoptose/efeitos dos fármacos , Carboplatina/farmacologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , Neoplasias do Endométrio/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fosfofrutoquinase-2/antagonistas & inibidores , Piridinas/farmacologia , Quinolinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Semin Cancer Biol ; 68: 21-30, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-31562955

RESUMO

Quinacrine, also known as mepacrine, has originally been used as an antimalarial drug for close to a century, but was recently rediscovered as an anticancer agent. The mechanisms of anticancer effects of quinacrine are not well understood. The anticancer potential of quinacrine was discovered in a screen for small molecule activators of p53, and was specifically shown to inhibit NFκB suppression of p53. However, quinacrine can cause cell death in cells that lack p53 or have p53 mutations, which is a common occurrence in many malignant tumors including high grade serous ovarian cancer. Recent reports suggest quinacrine may inhibit cancer cell growth through multiple mechanisms including regulating autophagy, FACT (facilitates chromatin transcription) chromatin trapping, and the DNA repair process. Additional reports also suggest quinacrine is effective against chemoresistant gynecologic cancer. In this review, we discuss anticancer effects of quinacrine and potential mechanisms of action with a specific focus on gynecologic and breast cancer where treatment-refractory tumors are associated with increased mortality rates. Repurposing quinacrine as an anticancer agent appears to be a promising strategy based on its ability to target multiple pathways, its selectivity against cancer cells, and the synergistic cytotoxicity when combined with other anticancer agents with limited side effects and good tolerability profile.


Assuntos
Antimaláricos/uso terapêutico , Antineoplásicos/uso terapêutico , Descoberta de Drogas , Reposicionamento de Medicamentos/métodos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Quinacrina/uso terapêutico , Animais , Humanos
18.
J Med Virol ; 93(3): 1296-1303, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32964419

RESUMO

The recent outbreak of the novel coronavirus, SARS-CoV-2, has emerged to be highly pathogenic in nature. Although lungs are considered as the primary infected organs by SARS-CoV-2, some of the other organs, including the brain, have also been found to be affected. Here, we have discussed how SARS-CoV-2 might infect the brain. The infection of the respiratory center in the brainstem could be hypothesized to be responsible for the respiratory failure in many COVID-19 patients. The virus might gain entry through the olfactory bulb and invade various parts of the brain, including the brainstem. Alternatively, the entry might also occur from peripheral circulation into the central nervous system by compromising the blood-brain barrier. Finally, yet another possible entry route could be its dispersal from the lungs into the vagus nerve via the pulmonary stretch receptors, eventually reaching the brainstem. Therefore, screening neurological symptoms in COVID-19 patients, especially toward the breakdown of the respiratory center in the brainstem, might help us better understand this disease.


Assuntos
Encéfalo/virologia , COVID-19/fisiopatologia , COVID-19/virologia , Vias Neurais/virologia , Centro Respiratório/virologia , SARS-CoV-2/patogenicidade , Animais , Encéfalo/patologia , Encéfalo/fisiopatologia , COVID-19/patologia , Citocinas/metabolismo , Humanos , Inflamação , Vias Neurais/fisiopatologia , Neurônios/virologia , Centro Respiratório/patologia , Centro Respiratório/fisiopatologia , Insuficiência Respiratória , Tropismo Viral
19.
SN Compr Clin Med ; 2(12): 2621-2630, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33134842

RESUMO

The COVID-19 pandemic has imposed a critical challenge to the current oncology care and practices including late diagnoses, delayed anti-cancer treatment, and static clinical trials. With the increasing risk of cancer patients acquiring infection during receiving the essential care, the debate ensues on how to balance the risk factors and benefits out of the oncologic emergencies in cancer patients. In this review article, we have focused on the current global re-organization of the integrity and effectiveness of the treatment modalities depending on the patient and cancer-specific urgencies while minimizing exposure to the infection. In this review, we addressed how the worldwide oncology community is united to share therapy schemes and the best possible guidelines to help cancer patients, and to strategize and execute therapy/trial protocols. This review provides collective knowledge on the current re-structuring of the general framework that prioritizes cancer care with the available exploitation of the reduced resources and most importantly the unparalleled levels of companionship as a large health care community towards the need to offer the best possible care to the patients.

20.
ACS Pharmacol Transl Sci ; 3(4): 786-787, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32832877

RESUMO

Both human B cell hybridoma technology and convalescent plasma therapy are promising immunological tools for therapeutic interventions. Here we propose using antibody producing B cells from convalescent SARS-CoV2 patients for developing human B cell hybridomas, and a combination of monoclonal antibodies against multiple immunogenic targets of SARS-CoV-2 spike protein might deliver an antibody cocktail for long-lasting therapeutic targeting.

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