Cantharidin is an active constituent of mylabris, a traditional Chinese medicine, and is a potent and selective inhibitor of protein phosphatase 2A (PP2A) that plays an important role in cell cycle ...control, apoptosis, and cell-fate determination. In the present study, we found that cantharidin repressed the invasive ability of pancreatic cancer cells and downregulated matrix metalloproteinase 2 (MMP2) expression through multiple pathways, including ERK, JNK, PKC, NF-κB, and β-catenin. Interestingly, transcriptional activity of the MMP2 promoter increased after treatment with PP2A inhibitors, suggesting the involvement of a posttranscriptional mechanism. By using an mRNA stability assay, we found accelerated degradation of MMP2 mRNA after treatment of cantharidin. Microarray analyses revealed that multiple genes involved in the 3' → 5' decay pathway were upregulated, especially genes participating in cytoplasmic deadenylation. The elevation of these genes were further demonstrated to be executed through ERK, JNK, PKC, NF-κB, and β-catenin pathways. Knockdown of PARN, RHAU, and CNOT7, three critical members involved in cytoplasmic deadenylation, attenuated the downregulation of MMP2. Hence, we present the mechanism of repressed invasion by cantharidin and other PP2A inhibitors through increased degradation of MMP2 mRNA by elevated cytoplasmic deadenylation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This study aimed to explore whether the combined application of desflurane and dexmedetomidine (Dex) reduces the occurrence of postoperative neurocognitive disorders (PND) in patients. We selected ...patients in our hospital who underwent surgery under general anesthesia, and divided them into two groups: Dex and desflurane (Dex + Des) and desflurane (Des) groups. The data of patients were collected and the Mini‐Mental State Examination (MMSE) score was used to assess cognitive status. The blood cell counts were determined preoperatively and on postoperative days 1, 3, and 6, and the percentage of neutrophils and lymphocytes were also recorded. The statistical methods used were the independent‐samples t‐test and the χ2 test. Pearson's correlation was used to analyze the correlation between PND and inflammation. The incidence of PND in the Dex + Des group was lower than that in the Des group. The postoperative MMSE scores in the Dex + Des group were higher than those in the Des group (p = 0.032). The percentage of neutrophils in the Dex + Des group was significantly lower than that in the Des group on the first and third days after surgery (p = 0.007; p = 0.028). The MMSE scores on the first day after surgery were negatively correlated with the multiple changes in white blood counts and the percentage of neutrophils (r = −0.3038 and −0.3330). Dex combined with Des reduced the incidence of PND and reduced the postoperative inflammatory cell counts.
Patients undergoing general anesthesia in our hospital were divided into desflurane and dexmedetomidine (Dex + Des) group and a desflurane (Des) group. Preoperative and postoperative MMSE scores, percentage of white blood cells, and neutrophil and lymphocyte counts were determined for postoperative exploration of whether the combined use of Des and Dex reduces the occurrence of PND in patients. The results showed that the combined use of Des and Dex could reduce the occurrence of postoperative PND and was negatively correlated with the postoperative inflammatory cell process.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Protein phosphatase 2A (PP2A) plays an important role in the control of the cell cycle. We previously reported that the PP2A inhibitors, cantharidin and okadaic acid (OA), efficiently repressed the ...growth of cancer cells. In the present study, we found that PP2A inhibitors arrested the cell cycle at the G2 phase through a mechanism that was dependent on the JNK pathway. Microarrays further showed that PP2A inhibitors induced expression changes in multiple genes that participate in cell cycle transition. To verify whether these expression changes were executed in a PP2A-dependent manner, we targeted the PP2A catalytic subunit (PP2Ac) using siRNA and evaluated gene expression with a microarray. After the cross comparison of these microarray data, we identified that CDK1 was potentially the same target when treated with either PP2A inhibitors or PP2Ac siRNA. In addition, we found that the down-regulation of CDK1 occurred in a JNK-dependent manner. Luciferase reporter gene assays demonstrated that repression of the transcription of CDK1 was executed through the JNK-dependent activation of the Sp1 transcription factor. By constructing deletion mutants of the CDK1 promoter and by using ChIP assays, we identified an element in the CDK1 promoter that responded to the JNK/Sp1 pathway after stimulation with PP2A inhibitors. Cantharidin and OA also up-regulated the expression of p21, an inhibitor of CDK1, via autophagy rather than PP2A/JNK pathway. Thus, this present study found that the PP2A/JNK/Sp1/CDK1 pathway and the autophagy/p21 pathway participated in G2/M cell cycle arrest triggered by PP2A inhibitors.
Breast cancer is one of the most common cancers affecting women worldwide. Conventional chemotherapy is still one of the major approaches to the treatment of breast cancer. Autophagy, also termed as ...type II programmed cell death (PCD), exhibits either a protumorigenic or antitumorigenic function. In the present study, we investigated whether autophagy could be involved in the effect of chemotherapy against breast cancer. Epirubicin, docetaxel, methotrexate, cyclophosphamide, fluorouracil (5-FU) and cisplatin were applied in the present investigation. All of these chemotherapeutics presented cytotoxicity against breast cancer cells. DsRed-LC3 reporter assay revealed that only docetaxel and cisplatin induced autophagy. Autophagy inhibitor 3-methyladenine (3-MA) strengthened the cytotoxicity of docetaxel, yet impaired the cytotoxicity of cisplatin, suggesting that docetaxel stimulates protumorigenic autophagy, while cisplatin-induced autophagy could be antitumorigenic. Real-time PCR revealed that cisplatin upregulated multiple autophagy-related genes, including AMBRA1, ATG3, ATG4C, ATG4D, ATG5, ATG7, ATG13, ATG14, ATG16L2, Beclin1, DRAM1, GABARAP, GABARAPL1, GABARAPL2, HDAC6, IRGM, MAP1LC3B and ULK1, indicating that cisplatin induced autophagy through a multiple mechanism involved manner.
Increasing evidence suggests that tumors are composed of a heterogeneous cell population with a small subset of cancer stem cells (CSCs) that sustain tumor formation and growth, and are hypothesized ...to account for therapeutic resistance. Based on the expression of the surface markers CD44, CD24, and EPCAM, putative CSCs have also been identified in pancreatic cancers. It has been well established that aberrant activation of β-catenin signaling pathway may contribute to the maintenance of CSCs. Cantharidin is an active constituent of mylabris, a traditional Chinese medicine. In our previous studies, we demonstrated that cantharidin treatment induced phosphorylation of β-catenin, leading to repression on β-catenin pathway. Therefore, in the present study, we investigated whether cantharidin and its derivant, norcantharidin, could repress the stemness of pancreatic cancer cells through repression on β-catenin pathway. By using microarray and flow cytometry, we found that treatment with cantharidin and norcantharidin repressed the expression of CD44, CD24, and EPCAM at both mRNA and protein levels, leading to decreased CD44+/CD24+/EPCAM+ proportion, the putative pancreatic CSC subset. Pretreatment with the β-catenin pathway inhibitor FH535, attenuated the cantharidin- and norcantharidin-inducrd repression on CD44, CD24, and EPCAM, suggesting cantharidin and its derivant repressed stemness of pancreatic cancer cells in β-catenin pathway-dependent manner. Furthermore, cantharidin and norcantharidin strengthened the cytotoxicity of gemcitabine and erlotinib, two well established pharmacotherapeutics against pancreatic cancers, indicating cantharidin and norcantharidin could be promising candidates for reversing drug resistance in pancreatic cancers. In conclusion, we presently propose that cantharidin and norcantharidin hold their promise in pancreatic cancer therapy through repression on stemness and strengthening the cytotoxicity of the present therapeutics.
The classifications and counts of white blood cells (WBCs) have been proved to be able to be used as prognostic markers in cancer cases. The present study investigated the potential values of the ...classifications and counts of WBC, including lymphocyte (LY), monocyte (MO), neutrophil (NE), eosinophil (EO), and basophil (BA) in the prognosis of resectable gastric cancers (GCs).
This retrospective study recruited 104 resectable GC cases which were pathologically confirmed. The patients were divided into two groups according to the median pre-treatment values. To evaluate the changes in WBC counts and classification after treatment, we introduced the concept of post/pre-treatment ratios (≤ 1 indicated count was not increased after therapy, while > 1 suggested increased count).
Pre-treatment NE and total WBC counts were negatively correlated with overall survival (OS). Surgery significantly decreased the level of NE count, but increased the level of EO, whereas had no effect on the levels of LY, MO, BAor total WBC. Adjuvant chemotherapy significantly decreased the level of BA. Whole course of treatment (surgery combined with adjuvant chemotherapy) had no significant effect on the counts of LY, MO, NE, EO, BA or total WBC. Post/pre-treatment ratios of LY, MO NE, EO, BA and total WBC levels had no effects on OS. Univariate analysis indicated that AJCC stage (III) and higher level of pre-treatment total WBC count were prognostic factors affecting OS. Multivariate Cox regression analysis revealed that AJCC stage (III) and higher level of pre-treatment total WBC count were independent prognostic factors.
Pre-treatment NE count and pre-treatment total WBC count may be potential prognostic factors for the prognostic evaluation of GCs.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The WNT/β-catenin pathway plays an important role in pancreatic cancer carcinogenesis. We evaluated the correlation between aberrant β-catenin pathway activation and the prognosis pancreatic cancer, ...and the potential of applying the β-catenin pathway inhibitor FH535 to pancreatic cancer treatment. Meta-analysis and immunohistochemistry showed that abnormal β-catenin pathway activation was associated with unfavorable outcome. FH535 repressed pancreatic cancer xenograft growth in vivo. Gene Ontology (GO) analysis of microarray data indicated that target genes responding to FH535 participated in stemness maintenance. Real-time PCR and flow cytometry confirmed that FH535 downregulated CD24 and CD44, pancreatic cancer stem cell (CSC) markers, suggesting FH535 impairs pancreatic CSC stemness. GO analysis of β-catenin chromatin immunoprecipitation sequencing data identified angiogenesis-related gene regulation. Immunohistochemistry showed that higher microvessel density correlated with elevated nuclear β-catenin expression and unfavorable outcome. FH535 repressed the secretion of the proangiogenic cytokines vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-8, and tumor necrosis factor-α, and also inhibited angiogenesis in vitro and in vivo. Protein and mRNA microarrays revealed that FH535 downregulated the proangiogenic genes ANGPT2, VEGFR3, IFN-γ, PLAUR, THPO, TIMP1, and VEGF. FH535 not only represses pancreatic CSC stemness in vitro, but also remodels the tumor microenvironment by repressing angiogenesis, warranting further clinical investigation.
Previous studies have indicated that inflammatory stimulation represses protein phosphatase 2A (PP2A), a well-known tumor suppressor. However, whether PP2A repression participates in pancreatic ...cancer progression has not been verified. We used lipopolysaccharide (LPS) and macrophage-conditioned medium (MCM) to establish in vitro inflammation models, and investigated whether inflammatory stimuli affect pancreatic cancer cell growth and invasion PP2A catalytic subunit (PP2Ac)-dependently. Via nude mouse models of orthotopic tumor xenografts and dibutyltin dichloride (DBTC)-induced chronic pancreatitis, we evaluated the effect of an inflammatory microenvironment on PP2Ac expression in vivo. We cloned the PP2Acα and PP2Acβ isoform promoters to investigate the PP2Ac transcriptional regulation mechanisms. MCM accelerated pancreatic cancer cell growth; MCM and LPS promoted cell invasion. DBTC promoted xenograft growth and metastasis, induced tumor-associated macrophage infiltration, promoted angiogenesis, activated the nuclear factor-κB (NF-κB) pathway, and repressed PP2Ac expression. In vitro, LPS and MCM downregulated PP2Ac mRNA and protein. PP2Acα overexpression attenuated JNK, ERK, PKC, and IKK phosphorylation, and impaired LPS/MCM-stimulated cell invasion and MCM-promoted cell growth. LPS and MCM activated the NF-κB pathway in vitro. LPS and MCM induced IKK and IκB phosphorylation, leading to p65/RelA nuclear translocation and transcriptional activation. Overexpression of the dominant negative forms of IKKα attenuated LPS and MCM downregulation of PP2Ac, suggesting inflammatory stimuli repress PP2Ac expression NF-κB pathway-dependently. Luciferase reporter gene assay verified that LPS and MCM downregulated PP2Ac transcription through an NF-κB-dependent pathway. Our study presents a new mechanism in inflammation-driven cancer progression through NF-κB pathway-dependent PP2Ac repression.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Abstract Protein phosphatase 2A (PP2A) is a multimeric serine/threonine phosphatase that can dephosphorylate multiple kinases. It is generally considered to be a cancer suppressor as its inhibition ...can induce phosphorylation and activation of substrate kinases that mainly accelerate growth. We previously reported that cantharidin, an active constituent of a traditional Chinese medicine, potently and selectively inhibited PP2A, yet efficiently repressed the growth of pancreatic cancer cells through activation of the c-Jun N-terminal kinase (JNK) pathway. This suggested that activation of kinase pathways might also be a potential strategy for cancer therapy. In this study, we have confirmed that the basal activity of the phospatidylinositol 3-kinase (PI3K)/JNK/activator protein 1 (AP-1) pathway promoted pancreatic cancer cell growth when stimulated by growth factors. Interestingly, although treatment with the PP2A inhibitors, cantharidin or okadaic acid (OA), amplified the PI3K-dependent activation of JNK, cell growth was repressed. We therefore hypothesised that a specific level of activity of the JNK pathway might be required to maintain the promitogenic function, as both repression and overactivation of JNK could inhibit cell proliferation. It was found that the JNK-dependent growth inhibition was independent of the activation of AP-1, but dependent on the repression of Akt. Although the PP2A inhibitors triggered overactivation of JNK and inhibited cell growth, excessively activated protein kinase C (PKC) improved cell survival. Combined treatment with a PP2A inhibitor and a PKC inhibitor produced a synergistic effect, which indicates a potentially promising therapeutic approach to pancreatic cancer treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Gastric cancer is the fourth most frequent cancer and the second cause of cancer-related deaths worldwide. China has a high incidence of gastric cancer. Inflammation is a critical component of tumor ...progression. It has been widely accepted that gastric cancer is an inflammation-driven cancer. In this study, we investigated the application value of systemic inflammatory response (SIR) markers, platelet to lymphocyte ratio (PLR) and neutrophil to lymphocyte ratio (NLR), in early diagnosis and prognostic prediction in patients with resectable gastric cancer.
One hundred and sixty-two patients with resectable gastric cancer were included and separated into groups according to median pre-operative PLR or NLR values (PLR low: < 208 or PLR high: ≥ 208, and NLR low: < 4.02 or NLR high: ≥ 4.02, respectively). To evaluate the changes in PLR or NLR values after operation, we introduced the concept of postpre-operative PLR or NLR ratios (< 1 indicated PLR or NLR values were decreased after operation, while ≥ 1 suggested not decreased PLR or NLR values).
Pre-operative PLR and NLR levels were significantly higher in gastric cancer patients compared with the healthy subjects. Low pre-operative PLR and NLR levels correlated with better clinicopathological features, including decreased depth of invasion, less lymph node metastasis and early tumor stage. Kaplan-Meier plots illustrated that higher pre-operative NLR and PLR had decreased overall survival (OS) and disease-free survival (DFS). Surgical tumor resection resulted in a significant
PLR and NLR measurements can provide important diagnostic and prognostic results in patients with resectable gastric cancer.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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