Paclitaxel inhibits breast cancer metastasis via suppression of Aurora kinase-mediated cofilin-1 activity

A new prognostic model including immune biomarkers, genomic proliferation tumor markers (AURKA and MYBL2) and clinical-pathological features optimizes prognosis in neoadjuvant breast cancer patients

Background

Up to 30% of breast cancer (BC) patients treated with neoadjuvant chemotherapy (NCT) will relapse. Our objective was to analyze the predictive capacity of several markers associated with immune response and cell proliferation combined with clinical parameters.

Methods

This was a single-center, retrospective cohort study of BC patients treated with NCT (2001-2010), in whom pretreatment biomarkers were analyzed: neutrophil-to-lymphocyte ratio (NLR) in peripheral blood, CD3+ tumor-infiltrating lymphocytes (TILs), and gene expression of AURKA, MYBL2 and MKI67 using qRT-PCR.

Results

A total of 121 patients were included. Median followup was 12 years. In a univariate analysis, NLR, TILs, AURKA, and MYBL2 showed prognostic value for overall survival. In multivariate analyses, including hormone receptor, HER2 status, and response to NCT, NLR (HR 1.23, 95% CI 1.01-1.75), TILs (HR 0.84, 95% CI 0.73-0.93), AURKA (HR 1.05, 95% CI 1.00-1.11) and MYBL2 (HR 1.19, 95% CI 1.05-1.35) remained as independent predictor variables.

Conclusion

Consecutive addition of these biomarkers to a regression model progressively increased its discriminatory capacity for survival. Should independent cohort studies validate these findings, management of early BC patients may well be changed.

Construction of Curcumin and Paclitaxel Co-Loaded Lipid Nano Platform and Evaluation of Its Anti-Hepatoma Activity in vitro and Pharmacokinetics in vivo

Purpose

The present study aimed to construct a co-loading platform encapsulating curcumin and paclitaxel at ratios of 2:1-80:1 (w/w) designated "CU-PTX-LNP" and explored the synergistic effects of CU-PTX at different composite proportions on liver cancer cells using the combination index (CI) method.

Methods

The CU lipid nanoplatform (CU-LNP) formulation was optimized via single-factor and orthogonal experiments. Various concentrations of PTX were added to the optimal formulation of CU-LNP to generate CU-PTX-LNP and the nanoplatform characterized via differential scanning calorimetry (DSC), transmission electron microscope (TEM), X-ray diffraction (XRD), zeta potential, polydispersity index (PDI), and size analyses. The cumulative release, stability, and cytotoxicity of CU-PTX-LNP in LO2, HepG2, and SMMC-7221 cells were assessed in vitro, followed by safety investigation and pharmacokinetic studies in vivo. The anti-tumor activity of CU-PTX-LNP was also evaluated using nude mice.

Results

CU-PTX-LNP formulations containing CU:PTX at a range of proportions (2:1-80:1; w/w) appeared as uniformly dispersed nanosized spherical particles with high entrapment efficiency (EE> 90%), sustained release and long-lasting stability. Data from in vitro cytotoxicity assays showed a decrease in the IC₅₀ value of PTX of CU-PTX-LNP (by 5.47-332.7 times in HepG2 and 4.29-143.21 times in SMMC-7221 cells) compared to free PTX. In vivo, CU-PTX-LNP displayed excellent biosafety, significant anti-tumor benefits and enhanced pharmacokinetic behavior with longer mean residence time (MRT_(0-t); CU: 4.31-fold, PTX: 4.61-fold) and half-life (t_1/2z; CU: 1.83-fold, PTX: 2.28-fold) relative to free drugs.

Conclusion

The newly designed CU-PTX-LNP platform may serve as a viable technological support system for the successful production of CU-PTX composite preparations.

Cofilin activation in pancreatic acinar cells plays a pivotal convergent role for mediating CCK-stimulated enzyme secretion and growth

Introduction: The actin regulatory protein, cofilin plays a key signaling role in many cells for numerous cellular responses including in proliferation, development, motility, migration, secretion and growth. In the pancreas it is important in islet insulin secretion, growth of pancreatic cancer cells and in pancreatitis. However, there are no studies on its role or activation in pancreatic acinar cells. Methods: To address this question, we studied the ability of CCK to activate cofilin in pancreatic acinar cells, AR42J cells and CCK₁-R transfected Panc-1 cells, the signaling cascades involved and its effect on enzyme secretion and MAPK activation, a key mediator of pancreatic growth. Results: CCK (0.3 and 100 nM), TPA, carbachol, Bombesin, secretin and VIP decreased phospho-cofilin (i.e., activate cofilin) and both phospho-kinetic and inhibitor studies of cofilin, LIM kinase (LIMK) and Slingshot Protein Phosphatase (SSH1) demonstrated these conventional activators of cofilin were not involved. Serine phosphatases inhibitors (calyculin A and okadaic acid), however inhibited CCK/TPA-cofilin activation. Studies of various CCK-activated signaling cascades showed activation of PKC/PKD, Src, PAK4, JNK, ROCK mediated cofilin activation, but not PI3K, p38, or MEK. Furthermore, using both siRNA and cofilin inhibitors, cofilin activation was shown to be essential for CCK-mediated enzyme secretion and MAPK activation. Conclusion: These results support the conclusion that cofilin activation plays a pivotal convergent role for various cell signaling cascades in CCK mediated growth/enzyme secretion in pancreatic acini.

Correlations of cofilin1 and phosphorylation at Ser3 site with sensitivity of elderly patients with non-small cell lung cancer to radiotherapy

Background: To explore the correlations of cofilin1 (CFL1) and phosphorylation level of locus serine residue at position 3 (Ser3) with the sensitivity of elderly patients with non-small cell lung cancer (NSCLC) to radiotherapy.

Methods: A total of 102 eligible patients treated from June 2013 to April 2015 were selected. The cases of complete remission and partial remission were included into radiotherapy-sensitive group (n=55), while those of stable disease and progressive disease were enrolled into radiotherapy-resistant group (n=47). Before treatment, tissues were collected to detect the expressions of CFL1 and CFL1 (phospho S3) by immunohistochemistry. The survival time and rate were recorded during follow-up.

Results: Compared with the radiotherapy-sensitive group, the radiotherapy-resistant group had advanced tumor-node-metastasis (TNM) stage and higher lymph node metastasis rate (P=0.000, 0.000). Compared with the tissues with negative CFL1 expression, the tissues with positive CFL1 expression had advanced TNM stage and higher lymph node metastasis rate (P=0.013, 0.000). The positive expression rate of CFL1 in the radiotherapy-resistant group was higher than that of the radiotherapy-sensitive group, whereas the positive expression rate of CFL1 (phospho S3) in the former was lower (P=0.000, 0.000). Lymph node metastasis, high CFL1 expression, and low CFL1 (phospho S3) expression were independent predictors for resistance to radiotherapy (P=0.001, 0.006, 0.003). In the radiotherapy-sensitive group, the patients with negative CFL1 expression and positive CFL1 (phospho S3) expression had long progression-free survival and high 5-year survival rate (P=0.000, 0.000).

Conclusion: The sensitivity to radiotherapy of elderly NSCLC patients is correlated negatively with CFL1 and positively with phosphorylation at locus Ser3. CFL1 and phosphorylation at locus Ser3 are independent predictors for sensitivity to radiotherapy.

Actin as a Target to Reduce Cell Invasiveness in Initial Stages of Metastasis

We demonstrate the relative roles of the cell cytoskeleton, and specific importance of actin in facilitating mechanical aspects of metastatic invasion. A crucial step in metastasis, the typically lethal spread of cancer to distant body-sites, is cell invasion through dense tissues composed of extracellular matrix and various non-cancerous cells. Cell invasion requires cell-cytoskeleton remodeling to facilitate dynamic morphological changes and force application. We have previously shown invasive cell subsets in heterogeneous samples can rapidly (2 h) and forcefully indent non-degradable, impenetrable, synthetic gels to cell-scale depths. The amounts of indenting cells and their attained depths provide the mechanical invasiveness of the sample, which as we have shown agrees with the in vitro metastatic potential and the in vivo metastatic risk in humans. To identify invasive force-application mechanisms, we evaluated changes in mechanical invasiveness following chemical perturbations targeting the structure and function of cytoskeleton elements and associated proteins. We evaluate effects on short-term (2-hr) indentations of single, well-spaced or closely situated cells as compared to long-time-scale Boyden chamber migration. We show that actomyosin inhibition may be used to reduce (mechanical) invasiveness of single or collectively invading cells, while actin-disruption may induce escape-response of treated single-cells, which may promote metastasis.

Paclitaxel-Loaded Macrophage Membrane Camouflaged Albumin Nanoparticles for Targeted Cancer Therapy

BACKGROUND

Melanoma is the most common symptom of aggressive skin cancer, and it has become a serious health concern worldwide in recent years. The metastasis rate of malignant melanoma remains high, and it is highly difficult to cure with the currently available treatment options. Effective yet safe therapeutic options are still lacking. Alternative treatment options are in great demand to improve the therapeutic outcome against advanced melanoma. This study aimed to develop albumin nanoparticles (ANPs) coated with macrophage plasma membranes (RANPs) loaded with paclitaxel (PTX) to achieve targeted therapy against malignant melanoma.

METHODS

Membrane derivations were achieved by using a combination of hypotonic lysis, mechanical membrane fragmentation, and differential centrifugation to empty the harvested cells of their intracellular contents. The collected membrane was then physically extruded through a 400 nm porous polycarbonate membrane to form macrophage cell membrane vesicles. Albumin nanoparticles were prepared through a well-studied nanoprecipitation process. At last, the two components were then coextruded through a 200 nm porous polycarbonate membrane.

RESULTS

Using paclitaxel as the model drug, PTX-loaded RANPs displayed significantly enhanced cytotoxicity and apoptosis rates compared to albumin nanoparticles without membrane coating in the murine melanoma cell line B16F10. RANPs also exhibited significantly higher internalization efficiency in B16F10 cells than albumin nanoparticles without a membrane coating. Next, a B16F10 tumor xenograft mouse model was established to explore the biodistribution profiles of RANPs, which showed prolonged blood circulation and selective accumulation at the tumor site. PTX-loaded RANPs also demonstrated greatly improved antitumor efficacy in B16F10 tumor-bearing mouse xenografts.

CONCLUSION

Albumin-based nanoscale delivery systems coated with macrophage plasma membranes offer a highly promising approach to achieve tumor-targeted therapy following systemic administration.

Resveratrol Enhances Apoptotic and Oxidant Effects of Paclitaxel through TRPM2 Channel Activation in DBTRG Glioblastoma Cells

Numerous studies have reported a strong association between increased production of reactive oxygen species (ROS) and the pathobiology of several diseases, and cancer in particular. Therefore, manipulation of cellular oxidative stress levels represents an important therapeutic target. Recently, resveratrol (RESV), a naturally occurring phytochemical, has been shown to sensitize several cell lines to the anticancer effects of other chemotherapeutic agents, including paclitaxel (PAX). However, the molecular mechanisms of action of RESV through oxidative sensitive TRPM2 channel activation remain unclear. The aim of this study was to evaluate the effect of combination therapy of RESV and PAX on activation of TRPM2 in DBTRG glioblastoma cells. DBTRG cells were divided into four treatment groups: control, RESV (50 μM), PAX (50 μM), and PAX + RESV for 24 hours. Our data shows that markers for apoptosis, mitochondrial membrane depolarization and mitochondrial function, intracellular steady-state ROS levels, caspase 3 activity, TRPM2 current density, and Ca²⁺ florescence intensity were significantly increased in DBTRG cells following treatment with PAX and RESV, respectively, although cell viability was also decreased by these treatments. These biochemical markers were further increased to favor the anticancer effects of PAX in DBTRG cells in combination with RESV. The PAX and RESV-mediated increase in current density and Ca²⁺ florescence intensity was decreased with a TRPM2 blocker. This suggests that for this combination therapy to have a substantial effect on apoptosis and cell viability, the TRPM2 channel must be stimulated.