Protein levels of clusterin and glutathione synthetase in platelets allow for early detection of colorectal cancer

Clusterin: a marker and mediator of chemoresistance in colorectal cancer

Intra-tumoural heterogeneity and cancer cell plasticity in colorectal cancer (CRC) have been key challenges to effective treatment for patients. It has been suggested that a subpopulation of LGR5-expressing cancer stem cells (CSCs) is responsible for driving tumour relapse and therapy resistance in CRC. However, studies have revealed that the LGR5+ve CSC population is highly sensitive to chemotherapy. It has been hypothesised that another subset of tumour cells can phenotypically revert to a stem-like state in response to chemotherapy treatment which replenishes the LGR5+ve CSC population and maintains tumour growth. Recently, a unique stem cell population marked by enriched clusterin (CLU) expression and termed the revival stem cell (RevSC) was identified in the regenerating murine intestine. This CLU-expressing cell population is quiescent during homeostasis but has the ability to survive and regenerate other stem cells upon injury. More recently, the CLU+ve signature has been implicated in several adverse outcomes in CRC, including chemotherapy resistance and poor patient survival; however, the mechanism behind this remains undetermined. In this review, we discuss recent insights on CLU in CRC and its roles in enhancing the plasticity of cells and further consider the implications of CLU as a prospective target for therapeutic intervention.

Elemene induces cell apoptosis via inhibiting glutathione synthesis in lung adenocarcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizome of Curcuma wenyujin Y.H. Chen & C. Ling, also known as Wen-E-Zhu, has been used for cancer treatment since ancient times, with roots dating back to the Song Dynasty. Elemene (EE), a sesquiterpene extract with potent anticancer properties, is extracted from Wen-E-Zhu, with β-elemene (BE) being its main active compound, along with trace amounts of β-caryophyllene (BC), γ-elemene and δ-elemene isomers. EE has demonstrated broad-spectrum anti-cancer effects and is commonly used in clinical treatments for various types of malignant cancers, including lung cancer. Studies have shown that EE can arrest the cell cycle, inhibit cancer cell proliferation, and induce apoptosis and autophagy. However, the exact mechanism of its anti-lung cancer activity remains unclear and requires further research and investigation.

AIM OF THE STUDY

In this study, the possible mechanism of EE and its main active components, BE and BC, against lung adenocarcinoma was investigated by using A549 and PC9 cell lines.

MATERIALS AND METHODS

The subcutaneous tumor model of nude mice was constructed to evaluate the efficacy of EE in vivo, then the in vitro half-inhibitory concentration (IC₅₀) of EE and its main active components, BE and BC, on A549 and PC9 cells at different concentrations were determined by CCK-8. Flow cytometry was used to detect the apoptosis and cycle of A549 and PC9 cells treated with different concentrations of BE and BC for 24 h. Non-targeted metabolomics analysis was performed on A549 cells to explore potential target pathways, which were subsequently verified through kit detection and western blot analysis.

RESULTS

Injection of EE in A549 tumor-bearing mice effectively suppressed cancer growth in vivo. The IC₅₀ of EE and its main active components, BE and BC, was around 60 μg/mL. Flow cytometry analysis showed that BE and BC blocked the G₂/M and S phases of lung adenocarcinoma cells and induced apoptosis, leading to a significant reduction in mitochondrial membrane potential (MMP). Results from non-targeted metabolomics analysis indicated that the glutathione metabolism pathway in A549 cells was altered after treatment with the active components. Kit detection revealed a decrease in glutathione (GSH) levels and an increase in the levels of oxidized glutathione (GSSG) and reactive oxygen (ROS). Supplementation of GSH reduced the inhibitory activity of the active components on lung cancer and also decreased the ROS content of cells. Analysis of glutathione synthesis-related proteins showed a decrease in the expression of glutaminase, cystine/glutamate reverse transporter (SLC7A11), and glutathione synthase (GS), while the expression of glutamate cysteine ligase modified subunit (GCLM) was increased. In the apoptosis-related pathway, Bax protein and cleaved caspase-9/caspase-9 ratio were up-regulated and Bcl-2 protein was down-regulated.

CONCLUSIONS

EE, BE, and BC showed significant inhibitory effects on the growth of lung adenocarcinoma cells, and the mechanism of action was linked to the glutathione system. By down-regulating the expression of proteins related to GSH synthesis, EE and its main active components BE and BC disrupted the cellular redox system and thereby promoted cell apoptosis.

A straightforward method to quantify circulating mRNAs as biomarkers of colorectal cancer

Optimizing the biomarker combination to be analyzed in liquid biopsies should improve personalized medicine. We developed a method to purify circulating cell-free mRNAs from plasma samples and to quantify them by RT-qPCR. We selected three candidate colorectal cancer biomarkers (B2M, TIMP-1, and CLU). Their mRNA levels were significantly higher in plasma of patients with metastatic colorectal cancer patients (mCRC) (n = 107) than in healthy individuals (HI) (n = 53). To increase the discriminating performance of our method, we analyzed the sum of the three mRNA levels (BTC index). The area under the ROC curve (AUC) to estimate the BTC index capacity to discriminate between mCRC and HI plasma was 0.903. We also determined the optimal BTC index cut-off to distinguish between plasma samples, with 82% of sensitivity and 93% of specificity. By using mRNA as a novel liquid biopsy analytical parameter, our method has the potential to facilitate rapid screening of CRCm.

Evaluation of Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio on Predicting Responsiveness to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Patients

Objective

Neutrophil-lymphocyte ratio (NLR) and Platelet-lymphocyte ratio (PLR) have been proposed as prognostic biomarkers in multiple cancers. However, the implications of NLR and PLR in the responsiveness to neoadjuvant chemoradiotherapy (nCRT) remain to be clarified in locally advanced rectal cancer (LARC) patients. This retrospective study investigated the prognostic value of NLR and PLR in nCRT responsiveness of LARC patients.

Methods

A total number of 86 patients diagnosed with LARC and treated with nCRT and total mesorectal excision were retrospectively followed from 2013 to 2016. Receiver operating characteristic (ROC) curve was used to determine the cutoff values of NLR and PLR, and the patients were divided into NLR elevation and NLR decrease groups, or PLR elevation and PLR decrease groups. The correlation between NLR and PLR changes, and clinicopathological factors were analyzed. The relationship between NLR and PLR changes and the curative responsiveness towards nCRT were further evaluated.

Results

NLR and PLR changes after nCRT were significantly correlated with the distance of tumors to the anus and BMI (body mass index) (P < 0.05). The clinical remission rate of patients with NLR reduction was 72.09% (31/43), which was significantly higher than that in patients with NLR increment (22/43, 51.16%). There was no significant difference in the clinic remission rate between the patients with PLR reduction and those with PLR increment (P > 0.05). However, the pathological responsiveness rate was significantly higher in patients with PLR reduction (21/43, 48.84%) when compared to the ones with PLR increment (9/43, 20.9%) (P = 0.036).

Conclusion

Our data indicate that in LARC patients with nCRT, the reduction of NLR and the reduction of PLR could serves as predictors for the clinic remission rate and pathological responsiveness rate, respectively. The combination of NLR and PLR changes may be employed as a simple and effective prognostic parameter to predict the treatment outcome of nCRT in LARC.

Alterations of the Platelet Proteome in Lung Cancer: Accelerated F13A1 and ER Processing as New Actors in Hypercoagulability

Simple Summary

The risk of venous thromboembolism in cancer is nine times higher than in the general population and the second leading cause of death in these patients. Tissue factor and downstream plasmatic coagulation cascade are largely responsible for the risk of thrombosis in cancer. In recent years, it has been increasingly recognised that platelets also play a central role in tumour growth and cancer-associated thrombosis. The underlying molecular mechanisms are largely unknown. In order to comprehensively investigate the biochemical changes in platelets from cancers with high risk of thrombosis, we examined the platelet proteome of brain and lung cancer patients in comparison to sex and age-matched healthy controls. However, we only found alterations in lung cancer, where some of these platelet proteins directly promote thrombosis. One example is the increased amount of the enzyme protein disulfide isomerase, which is clinically investigated as an antithrombotic drug target of the plant-based flavonol quercetin.

Abstract

In order to comprehensively expose cancer-related biochemical changes, we compared the platelet proteome of two types of cancer with a high risk of thrombosis (22 patients with brain cancer, 19 with lung cancer) to 41 matched healthy controls using unbiased two-dimensional differential in-gel electrophoresis. The examined platelet proteome was unchanged in patients with brain cancer, but considerably affected in lung cancer with 15 significantly altered proteins. Amongst these, the endoplasmic reticulum (ER) proteins calreticulin (CALR), endoplasmic reticulum chaperone BiP (HSPA5) and protein disulfide-isomerase (P4HB) were significantly elevated. Accelerated conversion of the fibrin stabilising factor XIII was detected in platelets of patients with lung cancer by elevated levels of a coagulation factor XIII (F13A1) 55 kDa fragment. A significant correlation of this F13A1 cleavage product with plasma levels of the plasmin–α-2-antiplasmin complex and D-dimer suggests its enhanced degradation by the fibrinolytic system. Protein association network analysis showed that lung cancer-related proteins were involved in platelet degranulation and upregulated ER protein processing. As a possible outcome, plasma FVIII, an immediate end product for ER-mediated glycosylation, correlated significantly with the ER-executing chaperones CALR and HSPA5. These new data on the differential behaviour of platelets in various cancers revealed F13A1 and ER chaperones as potential novel diagnostic and therapeutic targets in lung cancer patients.

Platelets as messengers of early-stage cancer

Platelets have an important role in tumor angiogenesis, growth, and metastasis. The reciprocal interaction between cancer and platelets results in changes of several platelet characteristics. It is becoming clear that analysis of these platelet features could offer a new strategy in the search for biomarkers of cancer. Here, we review the human studies in which platelet characteristics (e.g., count, volume, protein, and mRNA content) are investigated in early-stage cancer. The main focus of this paper is to evaluate which platelet features are suitable for the development of a blood test that could detect cancer in its early stages.

Glutathione Synthesis in Cancer Cells

Tripeptide GSH is associated not only with the control and maintenance of redox cell homeostasis, but also with the processes of detoxification, proliferation, cell differentiation, and regulation of cell death. Disruptions in GSH synthesis and changes in the GSH/GSSG ratio are common for many pathological conditions, including malignant neoplasms. Numerous data indicate the importance of GSH and the GSH/GSSG ratio in the regulation of tumor cell viability, in the initiation of tumor development, progression, and drug resistance. However, control of the mechanism of GSH synthesis in malignant tumors remains poorly understood. This review discusses the features of GSH synthesis and its regulation in tumor cells. The role of GSH in the mechanisms of apoptosis, necroptosis, ferroptosis, and autophagy is considered.

Inhibition Lysosomal Degradation of Clusterin by Protein Kinase D3 Promotes Triple-Negative Breast Cancer Tumor Growth

Triple negative breast cancer (TNBC), with its lack of targeted therapies, shows the worst mortality rate among all breast cancer subtypes. Clusterin (CLU) is implicated to play important oncogenic roles in cancer via promoting various downstream oncogenic pathways. Here, protein kinase D3 (PRKD3) is defined to be a key regulator of CLU in promoting TNBC tumor growth. Mechanically, PRKD3 with kinase activity binding to CLU is critical for CLU protein stability via inhibiting CLU's lysosomal distribution and degradation. CLU and PRKD3 protein level are significantly elevated and positively correlated in collected TNBC tumor samples. CLU silencer (OGX-011) and PRKDs inhibitor (CRT0066101) can both result in impressive tumor growth suppression in vitro and in vivo, suggesting targeting CLU and its key regulator-PRKD3 are promisingly efficient against TNBC. Finally, secreted CLU (sCLU) is found to be elevated in serums from TNBC patients and reduced in serum from TNBC murine models post OGX-011 and/or CRT0066101 treatment, suggesting serum sCLU is a promising blood-based biomarker for clinical management of TNBC. Taken together, this study provides a thorough molecular basis as well as preclinical evidences for targeting CLU pathway as a new promising strategy against TNBC via revealing PRKD3 as the key regulator of CLU in TNBC.

The canine activated platelet secretome (CAPS): A translational model of thrombin-evoked platelet activation response

BACKGROUND

Domestic dogs represent a translational animal model to study naturally occurring human disease. Proteomics has emerged as a promising tool for characterizing human platelet pathophysiology; thus a detailed characterization of the core canine activated platelet secretome (CAPS) will enhance utilization of the canine model. The objectives of this study were development of a robust, high throughput, label-free approach for proteomic identification and quantification of the canine platelet (i) thrombin releasate proteins, and (ii) the protein subgroup that constitutes CAPS.

METHODS

Platelets were isolated from 10 healthy dogs and stimulated with 50 nmol/L of γ-thrombin or saline. Proteins were in-solution trypsin-digested and analyzed by nano-liquid chromatography-tandem spectrometry. Core releasate proteins were defined as those present in 10 of 10 dogs, and CAPS defined as releasate proteins with a significantly higher abundance in stimulated versus saline controls (corrected P < .05).

RESULTS

A total of 2865 proteins were identified; 1126 releasate proteins were present in all dogs, 650 were defined as CAPS. Among the differences from human platelets were a canine lack of platelet factor 4 and vascular endothelial growth factor C, and a 10- to 20-fold lower concentration of proteins such as haptoglobin, alpha-2 macroglobulin, von Willebrand factor, and amyloid-beta A4. Twenty-eight CAPS proteins, including cytokines, adhesion molecules, granule proteins, and calcium regulatory proteins have not previously been attributed to human platelets.

CONCLUSIONS

CAPS proteins represent a robust characterization of a large animal platelet secretome and a novel tool to model platelet physiology, pathophysiology, and to identify translational biomarkers of platelet-mediated disease.

Decreased circulating clusterin reflects severe liver complications after hepatoportoenterostomy of biliary atresia

This study aimed to determine whether circulating levels of clusterin (CLU), an extracellular chaperone implicated in cholestatic and fibrotic processes, are associated with clinical parameters of post-operative BA patients and could serve as a BA biomarker. Ninety-six BA patients and 56 healthy controls were recruited. Circulating CLU levels were measured using enzyme-linked immunosorbent assay. Circulating CLU levels were significantly reduced in BA patients – especially those with worse outcomes including jaundice, severe liver fibrosis, and late-stage of hepatic dysfunction. Multivariate linear regression analysis revealed that circulating CLU levels were negatively associated with outcome parameters indicating jaundice status, degree of fibrosis, and liver dysfunction, but positively correlated with serum albumin and platelet number of BA patients. Lower circulating CLU levels were considerably associated with poor survival of post-operative BA patients. Receiver-operating characteristic curve analysis demonstrated a diagnostic value of circulating CLU as a non-invasive indicator for poor outcomes of BA patients (AUC = 0.85), with a sensitivity of 81.5% and a specificity of 73.5%. All findings indicate that reduced circulating CLU might reflect poor outcomes of BA patients and have potential as a novel biomarker for the disease severity following Kasai-operation.

Twelve Weeks of Whole Body Vibration Training Improve Regucalcin, Body Composition and Physical Fitness in Postmenopausal Women: A Pilot Study

(1) Background: Regucalcin or senescence marker protein 30 (SMP30) is a Ca2+ binding protein discovered in 1978 with multiple functions reported in the literature. However, the impact of exercise training on SMP30 in humans has not been analyzed. Aging is associated with many detrimental physiological changes that affect body composition, functional capacity, and balance. The present study aims to investigate the effects of whole body vibration (WBV) in postmenopausal women. (2) Methods: A total of 13 women (aged 54.3 ± 3.4 years) participated in the study. SMP30, body composition (fat mass, lean mass, and bone mass) and physical fitness (balance, time up and go (TUG) and 6-min walk test (6MWT)) were measured before and after the 12 weeks of WBV training. (3) Results: The WBV training program elicited a significant increase in SPM30 measured in plasma (27.7%, p = 0.004) and also in 6MWT (12.5%, p < 0.001). The WBV training also significantly reduced SPM30 measured in platelets (38.7%, p = 0.014), TUG (23.1%, p < 0.001) and total body fat mass (4.4%, p = 0.02). (4) Conclusions: There were no significant differences in balance, lean mass or bone mass. The present study suggests that 12 weeks of WBV has the potential to improve SPM30, fat mass, TUG and 6MWT in postmenopausal women.

Perioperative changes of inflammation-based biomarker for predicting the prognosis in colorectal cancer patients: a retrospective analysis

Introduction

Perioperative inflammatory markers, including the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), are associated with oncological prognosis. However, their changes in colorectal cancer surgery for predicting the prognosis are rarely investigated.

Aim

To compare perioperative changes to evaluate the prognostic significance of patients’ survival.

Material and methods

Retrospective clinical data and baseline laboratory parameters of 183 colorectal cancer (CRC) patients who underwent curative surgery were collected between January 2007 and January 2013. The clinicopathological characteristics were compared. Statistical analysis was used to identify the predictive changes of perioperative NLR and PLR associated with survival prognosis.

Results

ROC analysis indicated that perioperative NLR/PLR showed higher predictive accuracy for prognosis, and the optimal cut-off values of pre-NLR, post-NLR, pre-PLR, and post-PLR were 2.94, 4.32, 184.29, and 212.37, respectively. Kaplan-Meier analysis suggested that the four groups stratified by perioperative changes had significantly different recurrence-free survival and overall survival (p < 0.05). Univariate and multivariable analysis revealed that patients with higher cancer stage, lymph node metastasis, and perioperative change of NLR/PLR (HH, LH) had significant association with poor prognosis of RFS and OS (all p < 0.05).

Conclusions

Perioperative NLR and PLR might be good predictors for prognosis in CRC patients who have undergone curative surgery, which could guide the customised therapeutic strategy. Furthermore, their assessment could contribute to accurately predicting oncologic outcomes and provide an in-depth understanding of the patients, which could guide the operational strategy.

PD-L1 is expressed on human platelets and is affected by immune checkpoint therapy

Cancer immunotherapy has been revolutionised by drugs that enhance the ability of the immune system to detect and fight tumors. Immune checkpoint therapies that target the programmed death-1 receptor (PD-1), or its ligand (PD-L1) have shown unprecedented rates of durable clinical responses in patients with various cancer types. However, there is still a large fraction of patients that do not respond to checkpoint inhibitors, and the challenge remains to find cellular and molecular cues that could predict which patients would benefit from these therapies. Using a series of qualitative and quantitative methods we show here that PBMCs and platelets from smokers and patients with head and neck squamous cell carcinoma (HNSCC) or lung cancer express and up-regulate PD-L1 independently of tumor stage. Furthermore, treatment with Atezolizumab, a fully humanised monoclonal antibody against PD-L1, in 4 patients with lung cancer caused a decrease in PD-L1 expression in platelets, which was restored over 20 days. Altogether, our findings reveal the expression of the main therapeutic target in current checkpoint therapies in human platelets and highlight their potential as biomarkers to predict successful therapeutic outcomes.