ABSTRACT
Pancreatic adenocarcinoma (PAAD) is one of the most lethal malignancies. Although gemcitabine (GEM) is a standard treatment for PAAD, resistance limits its application and therapy. Secoemestrin C (Sec C) is a natural compound from the endophytic fungus Emericella, and its anticancer activity has not been investigated since it was isolated. Our research is the first to indicate that Sec C is a broad-spectrum anticancer agent and could exhibit potently similar anticancer activity both in GEM-resistant and GEM-sensitive PAAD cells. Interestingly, Sec C exerted a rapid growth-inhibiting effect (80% death at 6 h), which might be beneficial for patients who need rapid tumor shrinkage before surgery. Liquid chromatography/mass spectrometry and N-acetyl-l-cysteine (NAC) reverse assays show that Sec C sulfates cysteines to disrupt disulfide-bonds formation in endoplasmic reticulum (ER) proteins to cause protein misfolding, leading to ER stress and disorder of lipid biosynthesis. Microarray data and subsequent assays show that ER stress-mediated ER-associated degradation (ERAD) ubiquitinates and downregulates YAP to enhance ER stress via destruction complex (YAP-Axin-GSK-βTrCP), which also elucidates a unique degrading style for YAP. Potent anticancer activity in GEM-resistant cells and low toxicity make Sec C a promising anti-PAAD candidate.
ABSTRACT
With the recent understanding of cancer biology, physiopathology, and cancer genetics& genomics, new treatments and methodologies are constantly developed, including on the development and application of molecular targeted drugs for cancer therapy have been widespread concerned.Antibody-based drugs targeting over-expressed oncogenes or other functional proteins in cancer with its high specificity, less side-effects and significant clinical efficacy became rapidly the hot-spot of anti-tumor drug research.Currently, there are already more than 20 of anti-tumor antibody-based drugs approved for clinical application, and achieved remarkable results.This article summarizes the development and current situation of monoclonal antibody-based drug research for cancer therapy, as well as their anti-tumor mechanism of action.At the same time summarizes the new advances in cancer research in the field of monoclonal antibody drugs made,and its prospects as well as shortcomings were outlined.
ABSTRACT
Retinoblastoma is the most common pediatric retinal tumor initiated by biallelic inactivation of the retinoblastoma gene ( RB1 ) , affecting roughly 1 in 15000 children with 1100 new cases each year.In China, RB remains a potentially devastating disease while lack of early diagnosis and aggressive treatment strategies.Moreover, RB patients individually show a variety of drug response to regular systemic chemotherapy since intensive chemotherapy and long-term follow-up are not as readily available.The majority of patients with advanced diseases require enucleation which affects the future quality of children life.Recent studies showed that alterations in genomics and epigenomics of RB play very important roles in RB progress and therapy.We thereby review current understanding changes of genomics and epigenomics in RB as potential prognostic and therapeutic targets.
ABSTRACT
Autophagy is a classical regulatory mechanism of energy metabolism and self-update system in the maintenance of the intracellular homeostasis and cell development. Autophagy has been recently found to play a role in tumor development. Autophagy regulates tumor formation, proliferation, metastasis, and metabolism. At the same time, the anticancer drugs formed with autophagic mediators have been used in the treatment, which suggested that improving autophagy activity to inhibit tumor has become a new way for cancer treatment of cancer patients. This article gives an overview of the regulatory mechanism of autophagy, the relationship between autophagy and tumor, and tumor therapy by targeting autophagy.
ABSTRACT
Taking 12-N-p-chlorobenzyl sophoridinol 2 as a lead, a series of novel sophoridinic derivatives with various 3'-substituents at the 11-side chain were synthesized and evaluated for their anticancer activity from sophoridine (1), a natural antitumor medicine. Among them, the sophoridinic ketones 5a-b, alkenes 7a-b and sophoridinic amines 14a-b displayed reasonable antiproliferative activity with IC50 values ranging from 3.8 to 5.4 μmol/L. Especially, compounds 5a and 7b exhibited an equipotency in both adriamycin (AMD)-susceptible and resistant MCF-7 breast carcinoma cells, indicating a different mechanism from AMD. The primary mechanism of action of 5a was to arrest the cell cycle at the G0/G1 phase, consistent with that of parent compound 1. Thus, we consider 12-chlorobenzyl sophoridinic derivatives with a tricyclic scaffold to be a new class of promising antitumor agents with an advantage of inhibiting drug-resistant cancer cells.
ABSTRACT
Epithelial-mesenchymal transition (EMT) refers to tne transition during which epithelial cells undergo the loss of apical-basal polarity, acquisition of migration capability and transformation into mesenchymal cells. EMT induces breast cancer in situ to developing into metastasis and associates with the drug resistence. The multiple elements including signal pathways, transcriptional factors and downstream genes orchestrate the transition. Among them, the transforming growth factor β (TGF-β) signaling pathway plays a key role in the regulation of EMT in breast cancer. And this paper reviews the development of TGF-β signaling pathway induced EMT in breast cancer.
ABSTRACT
For screening the potential drugs as anti-liver fibrosis candidates, we established a high- throughput drug screening cell model based on COL1A1 promoter. The activity of COL1A1 promoter and luciferase reporter gene can be elevated by TGF-β1, and inhibited by candidate drugs. We constructed a recombined plasmid with COL1A1 promoter and luciferase reporter gene pGL4.17, the activity of COL1A1 promoter was reflected by fluorescence intensity. COL1A1 promoter activity was detected by Dual-Luciferase Reporter Assay System, it came that the relative luciferase activity of COL1A1 promoter was 15.98 times higher than that of control group induced by TGF-β1, showing the recombined plasmid could be used in cell model. The recombined plasmid was transfected into human hepatic stellate cells LX2, detected the effect of potential drugs, and obtained a stable expression system through stable transfection and monoclonal cell culture. A sample which could reduce COL1A1 promoter activity signally by our cell model, decreased collagen I mRNA and protein expression detected by real-time RT-PCR and Western blotting. It indicates this novel cell model can be used in high-throughput drug screening of potential anti-liver fibrosis drugs.
ABSTRACT
Aim To investigate the relationship be-tween phosphoprotein EBP50 and the proliferation of breast cancer in MCF-7 cells. Methods The quali-fied recombinant plasmid sh-EBP50-pGPU6/Neo was transfected into MCF-7 cells with EBP50 knocking down. The expression of EBP50, c-myc, p-ERK1/2, and ERK1/2 was detected by Western blot. The prolif-eration ability of cells was detected by sulforhodamine B assay. Results The EBP50 knocking down plasmid was constructed successfully. MCF-7 cells with EBP50 knocking down had been established successfully. Knocking down of EBP50 increased the proliferation of MCF-7 significantly, and partially augmented the ex-pression of c-myc and phosphorylation of ERK1/2 . However, knocking down of EBP50 did not impact the expression of ERK1/2 . Conclusion EBP50 suppres-ses the proliferation of breast cancer cell through inhib-iting the activity of ERK1/2 in MCF-7 cell line.
ABSTRACT
In this study, N-terminal site-specific mono-PEGylation of the recombinant lidamycin apoprotein (rLDP) of lidamycin (LDM) was prepared using a polyethyleneglycol (PEG) derivative (M w 20 kDa) through a reactive terminal aldehyde group under weak acidic conditions (pH 5.5). The biochemical properties of mPEG-rLDP-AE, an enediyne-integrated conjugate, were analyzed by SDS-PAGE, RP-HPLC, SEC-HPLC and MALDI-TOF. Meanwhile, in vitro and in vivo antitumor activity of mPEG-rLDP-AE was evaluated by MTT assays and in xenograft model. The results indicated that mPEG-rLDP-AE showed significant antitumor activity both in vitro and in vivo. After PEGylation, mPEG-rLDP still retained the binding capability to the enediyne AE and presented the physicochemical characteristics similar to that of native LDP. It is of interest that the PEGylation did not diminish the antitumor efficacy of LDM, implying the possibility that this derivative may function as a payload to deliver novel tumor-targeted drugs.
ABSTRACT
Liver fibrosis is a pathological process of the excessive accumulation of extracellular matrix, especially collagen al (I) in liver. Ultimately, hepatic fibrosis leads to cirrhosis or hepatic failure. Liver fibrosis and early cirrhosis can be reversed, thus control of the development of liver fibrosis is very important for preventive treatment of cirrhosis and hepatic failure. This is a review of potential targets for anti-hepatic fibrosis based on plenty of publications, including TGF-β1 and integrin α(v) and so on, aimed at providing novel therapeutic targets in liver fibrosis.
ABSTRACT
To increase the efficacy of currently used anti-cancer genotoxins, one of the current efforts is to find agents that can sensitize cancer cells to genotoxins so that the efficacious doses of genotoxins can be lowered to reduce deleterious side-effects. In this study, we reported that a synthetic RasGAP-derived peptide GAP159 could enhance the effect of chemotherapeutic agent cisplatin (CDDP) in human colon carcinoma HCT116 cells. Our results showed that GAP159 significantly increased the CDDP-induced cytotoxicity and apoptosis in HCT116 cells. This synergistic effect was associated with the inhibitions of phospho-AKT, phospho-ERK and NF-κB. In mouse colon tumor CT26 animal models, GAP159 combined with CDDP significantly suppressed CT26 tumor growth, and GAP159 alone showed slight inhibitory effect. Our data suggests that co-treatment of GAP159 and chemotherapeutics will become a potential therapeutic strategy for colon cancers.
ABSTRACT
Sphingosine kinase 1 (SphK1) plays critical roles in cell biological functions. Here we investigated the effects of SphK1 inhibitor SKI II on hepatoma HepG2 cell cycle progression and invasion. Cell survival was determined by SRB assay, cell cycle progression was assayed by flow cytometry, the ability of cell invasion was measured by Matrigel-Transwell assay and protein expression was detected by Western blotting. The results showed that SKI II markedly inhibited HepG2 cell survival in a dose-dependent manner, induced G1 phase arrest in HepG2 cell and inhibited cell invasion. SKI II markedly decreased the expressions of G1-phase-related proteins CDK2, CDK4 and Cdc2 and the levels of cell invasion-associated proteins MMP2 and MMP9. The results showed that SKI II inhibited cell cycle progression and cell invasion, implying SphK1 as a potential target for hepatoma treatment.
ABSTRACT
This study aimed to investigate the synergistic effect of lidamycin (LDM) and rituximab on human B cell lymphoma Ramos cells. Cell proliferation was measured using MTS assay, cell apoptosis was analyzed by Annexin V-FITC/PI assay, the expression of apoptosis related proteins was analyzed by Western blotting, and the in vivo lymphoma inhibition was verified using BALB/c mice inoculated via tail vein using Ramos cells which stably expressed pEGFP-N1 plasmid. The results showed that, after the pretreatment with rituximab for 48 h, rituximab and LDM showed significantly synergistic effects on cell proliferation. Cells in combined treatment group had a higher apoptosis rate than that in LDM treatment group. Compared with the LDM treatment group, the expression of apoptosis-related proteins such as Cleaved caspase-3, Cleaved caspase-7, Cleaved caspase-9 and Cleaved PARP in combined treatment groups increased, and expression of cIAP-2 and Bcl-2 decreased. The result of in vivo experiment showed that, in the combined treatment group, the survival time of BALB/c mice was significantly longer than the mice in control group and LDM treatment group, and the degree of tumor accumulation and metastasis to lymph nodes and spleen was lower.
ABSTRACT
Sphingolipids as an important regulator play a critical role in the cell biological functions. Among them, ceramide (Cer) and sphingosine (Sph) induce apoptosis and inhibit cell proliferation; on the contrary sphingosine 1-phosphate (S1P) promotes cell survival and proliferation. The balance between ceramide/sphingosine and S1P forms a so-called "sphingolipid-rheostat", which decides the cell fate. Sphingosine kinases, which catalyze the phosphorylation of sphingosine to S1P, are critical regulators of this balance. Here, we review the role of sphingosine kinase 1 (SphK1) in regulating fundamental biological processes and tumorigenesis and the potential of SphK1 as a new target for cancer therapeutics.
ABSTRACT
A series of cycloberberine derivatives were designed, synthesized and evaluated for their anti-cancer activities in vitro. Among these analogs, compounds 6c, 6e and 6g showed strong inhibition on human HepG2 cells. They afforded a potent effect against DOX-resistant MCF-7 breast cells as well. The primary mechanism showed that cell cycle was blocked at G2/M phase of HepG2 cells treated with 6g using flow cytometry assay. It significantly inhibited the activity of DNA Top I at the concentration of 0.1 mg mL-1. Our results provided a basis for the development of this kind of compounds as novel anti-cancer agents.
ABSTRACT
A series of novel N-(2-arylethyl) isoquinoline derivatives were designed, synthesized and evaluated for their anti-cancer activities. Among these analogs, compound 9a exhibited the potential anti-cancer activities on HepG2 and HCT116 cells with IC50 values of 2.52 and 1.99 microg x mL(-1), respectively. Cell cycle was blocked at S phase of HepG2 cells treated with 9a by flow cytometry detection. Our results provided a basis for the development of a new series of anti-cancer candidates.
ABSTRACT
The use of monoclonal antibodies (mAbs) for cancer therapy has achieved considerable success in recent years. Approximate 17 monoclonal antibodies have been approved as cancer therapeutics since 1997. Antibody-drug conjugates (ADC) are powerful new treatment options for cancer, and naked antibodies have recently achieved remarkable success. The safety and effectiveness of therapeutic mAbs in oncology vary depending on the nature of the target antigen and the mechanisms of tumor cell killing. This review provides a summary of the current state of antibody-based cancer therapy, including the mechanisms of tumor cell killing by antibodies, tumor antigens as antibody targets, clinical effectiveness of antibodies in cancer patients and nanoparticles-based ADCs.
ABSTRACT
Objective To study the in vivo expression and biodistribution of Ad5-Fluc (Adenovirus carrying firefly luciferase genes) in mice.Methods The recombinant Ad5-Fluc virus was constructed and infected to BALB/c or nude mice through three different routes.The protein expression level,tissue distribution and the characteristics of infection were analyzed by in vivo bioluminescence imaging technology.Results Compared to other two routes,the BALB/c mice infected through muscular route had the longest expression cycle (over 60 days) and the highest expression level,while the virus was transferred into the liver and spleen after infection.The nude mice had a significantly extended expression cycle than BALB/c mice.Moreover,the characteristic of liver tropism was eliminated after Ad5 F35 infection in mice,while maintained similar expression efficiency.Conclusion Due to the highest expression efficiency,the muscular route would be the optimal route for Ad5 vector based vaccination.In addition,Ad5F35 virus could become an ideal alternative vaccine vector for eliminating the liver tropism.
ABSTRACT
Objective To detect the protection induced by HPV-58 L2 11-200 AA in animal, and analyze the relationship between antibody or neutralizing antibody titers and the protection generated by the immunizmg agent. Methods The peptide of HPV-58 L2 11-200 AA was expressed in E. coli and the mice were immunized with the peptide after purification and adsorption with aluminum adjuvant. The protection provided by different immunizing doses was detected in the mouse model against the challenge of the pseud-ovirions of human papiilomavirus types 58. The total antibodies and neutralizing antibody titers of serum were tested with ELISA and neutralization assay against HPV-58 pseudovirus, respectively. The total antibodies or neutralizing antibody titers that can protect the mouse from infection were analyzed. Results The mice can be protected from the challenge with HPV pseudovirus when the immunizing dose was 8 μg. The neutralizing antibody can not be detected in the immune serum by neutralization assay against pseudovirus. The total anti-body level has a corresponding relationship with the protection showed in mouse model. The results of total antibodies detected by ELISA showed that when the titer of total antibodies was ≥25 000, luminescent signal can not be detected and the mice can be protected from pseudovirus infection. Conclusion HPV-58 L2 11-200 AA peptide can protect mice from pseudovirus infection. L2 peptide has a promising perspective to be a candidate vaccine and the level of total antibodies in the immune serum can be used as a surrogate for the evaluation of protection against HPV infection.
ABSTRACT
To investigate the antitumor activities of the immunoconjugates composed of anti-type IV collagenase monoclonal antibody Fab' fragment and lidamycin (LDM) prepared with different linkers. The immunoconjugates were prepared by linking Fab' to lysine-69 of LDM apoprotein by SPDP, LCSPDP, SMBS or SSMPB as the intermediate drug linkers. Immunoreactivities of the conjugates were determined by ELISA. The cytotoxicities of the conjugates were examined by clonogenic assay. In vivo antitumor effects of the conjugates were evaluated in nude mice bearing subcutaneously implanted HT-1080 tumor. ELISA assay showed that the conjugates retained part of the immunoreactivity of 3G11 against the antigen. The cytotoxicities of the Fab'-SMBS-LDM and Fab'-SSMPB-LDM to HT-1080 cells were significantly potent, compared with Fab'-SPDP-LDM, Fab'-LCSPDP-LDM and free LDM. In animal models at the same condition, free LDM, Fab'-SPDP-LDM and Fab'-LCSPDP-LDM inhibited the growth of HT-1080 tumor by 70.9%, 74.8% and 72.3%, while Fab'-SMBS-LDM and Fab'-SSMPB-LDM reached 78.0% and 87.7%, respectively. The median survival time of the mice treated with free LDM, Fab'-SPDP-LDM and Fab'-LCSPDP-LDM were prolonged by 71.9%, 82.2% and 107.5%, respectively, compared with that of untreated group. Whereas, the median survival time of Fab'-SMBS-LDM and Fab'-SSMPB-LDM were prolonged by 145.2% and 165.8%, respectively, indicating that Fab'-SSMPB-LDM was more effective than Fab'-SMBS-LDM in tumor suppression and life span prolongation. Fab'-SSMPB-LDM has more marked selective antitumor efficacy and lower toxicity, and might be a novel candidate for cancer therapy.