Cancer and Thrombosis: The Platelet Perspective

miRNA Profiling of Magnetic Nanopore-Isolated Extracellular Vesicles for the Diagnosis of Pancreatic Cancer

Improved diagnostics for pancreatic ductal adenocarcinoma (PDAC) to detect the disease at earlier, curative stages and to guide treatments is crucial to progress against this disease. The development of a liquid biopsy for PDAC has proven challenging due to the sparsity and variable phenotypic expression of circulating biomarkers. Here we report methods we developed for isolating specific subsets of extracellular vesicles (EV) from plasma using a novel magnetic nanopore capture technique. In addition, we present a workflow for identifying EV miRNA biomarkers using RNA sequencing and machine-learning algorithms, which we used in combination to classify distinct cancer states. Applying this approach to a mouse model of PDAC, we identified a biomarker panel of 11 EV miRNAs that could distinguish mice with PDAC from either healthy mice or those with precancerous lesions in a training set of n = 27 mice and a user-blinded validation set of n = 57 mice (88% accuracy in a three-way classification). These results provide strong proof-of-concept support for the feasibility of using EV miRNA profiling and machine learning for liquid biopsy.Significance: These findings present a panel of extracellular vesicle miRNA blood-based biomarkers that can detect pancreatic cancer at a precancerous stage in a transgenic mouse model. Cancer Res; 78(13); 3688-97. ©2018 AACR.

Higher platelet distribution width predicts poor prognosis in laryngeal cancer

BACKGROUND

Activated platelets promote cancer progression and metastasis. However, the prognostic value of platelet indices in laryngeal cancer remains poorly understood. The purpose of this study was to investigate the predictive significance of platelet indices in laryngeal cancer.

RESULTS

Of the 241 patients, high platelet distribution width (PDW) levels were observed in 116 (48.1 %) patients. In the Kaplan-Meier analysis, increased PDW was significantly associated with a poorer overall survival (p < 0.001). In the multivariate Cox model, PDW was an independent prognostic index for overall survival (HR=4.381, 95% CI=2.313-8.298, P < 0.001).

METHOD

The retrospective study included 241 consecutive patients with laryngeal cancer between January 2009 and December 2009. The relationships between PDW and clinicopathological characteristics were analyzed. Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of PDW.

CONCLUSIONS

Elevated PDW might be a novel prognostic marker in laryngeal cancer.

Platelet Metabolism and Other Targeted Drugs; Potential Impact on Immunotherapy

The role of platelets in cancer progression has been well recognized in the field of cancer biology. Emerging studies are elaborating further the additional roles and added extent that platelets play in promoting tumorigenesis. Platelets release factors that support tumor growth and also form heterotypic aggregates with tumor cells, which can provide an immune-evasive advantage. Their most critical role may be the inhibition of immune cell function that can negatively impact the body’s ability in preventing tumor establishment and growth. This review summarizes the importance of platelets in tumor progression, therapeutic response, survival, and finally the notion of immunotherapy modulation being likely to benefit from the inclusion of platelet inhibitors.

Cancer and platelet crosstalk: opportunities and challenges for aspirin and other antiplatelet agents

Platelets have long been recognized as key players in hemostasis and thrombosis; however, growing evidence suggests that they are also significantly involved in cancer, the second leading cause of mortality worldwide. Preclinical and clinical studies showed that tumorigenesis and metastasis can be promoted by platelets through a wide variety of crosstalk between platelets and cancer cells. For example, cancer changes platelet behavior by directly inducing tumor-platelet aggregates, triggering platelet granule and extracellular vesicle release, altering platelet phenotype and platelet RNA profiles, and enhancing thrombopoiesis. Reciprocally, platelets reinforce tumor growth with proliferation signals, antiapoptotic effect, and angiogenic factors. Platelets also activate tumor invasion and sustain metastasis via inducing an invasive epithelial-mesenchymal transition phenotype of tumor cells, promoting tumor survival in circulation, tumor arrest at the endothelium, and extravasation. Furthermore, platelets assist tumors in evading immune destruction. Hence, cancer cells and platelets maintain a complex, bidirectional communication. Recently, aspirin (acetylsalicylic acid) has been recognized as a promising cancer-preventive agent. It is recommended at daily low dose by the US Preventive Services Task Force for primary prevention of colorectal cancer. The exact mechanisms of action of aspirin in chemoprevention are not very clear, but evidence has emerged that suggests a platelet-mediated effect. In this article, we will introduce how cancer changes platelets to be more cancer-friendly and highlight advances in the modes of action for aspirin in cancer prevention. We also discuss the opportunities, challenges, and opposing viewpoints on applying aspirin and other antiplatelet agents for cancer prevention and treatment.

Platelet RNA signatures for the detection of cancer

Platelets are equipped with RNA processing machineries, such as pre-mRNA splicing, pre-miRNA processing, and mRNA translation. Since platelets are devoid of a nucleus, most RNA transcripts in platelets are derived from megakaryocytes during thrombocytogenesis. However, platelets can also ingest RNA molecules during circulation and/or interaction with other cell types. Since platelets were first described by Bizzozero in 1881, their well-established role in hemostasis and thrombosis has been intensively studied. However, in the past decades, the list of biological processes in which platelets play an important role keeps expanding. In this review, we discuss how platelet RNA biomarker signatures can be altered in the presence of cancer.

Pretreatment platelet count as a prognostic factor in patients with pancreatic cancer: a systematic review and meta-analysis

Background

The relationship between platelet counts and pancreatic cancer as a prognostic factor has been reported in many studies. We aimed to evaluate the prognostic value of platelet counts in predicting the prognosis of pancreatic cancer patients.

Methods

We searched PubMed, Medline, EMBASE, and Google Scholar for eligible studies up to May 2017. Information about the characteristics of the study and relevant outcomes was extracted. A meta-analysis was performed to analyze the prognostic value of platelet counts using the hazard ratio (HR) and 95% confidence intervals (CIs).

Results

A total of 1,756 patients in 13 retrospective studies were included. The pooled HR of 1.51 (95% CI: 1.20–1.90, P<0.001) showed that patients with elevated platelet counts were expected to have poor overall survival after treatment. Subgroup analysis showed that prognostic value of platelet levels was stronger in patients who received surgical resection (HR =1.60, 95% CI: 1.09–2.34, P=0.02), followed by patients who received palliative therapy (HR =1.46, 95% CI: 1.03–2.06, P=0.03).

Conclusion

Platelet counts could be a useful prognostic marker for pancreatic cancer. Patients with high platelet counts are expected to have poor survival.

Fluorinated Analog NMR s of Organosulfur Compounds from Garlic (Allium sativum): Synthesis, Chemistry and Anti-Angiogenesis and Antithrombotic Studies

We describe the synthesis, reactivity, and antithrombotic and anti-angiogenesis activity of difluoroallicin (S-(2-fluoroallyl) 2-fluoroprop-2-ene-1-sulfinothioate) and S-2-fluoro-2-propenyl-l-cysteine, both easily prepared from commercially available 3-chloro-2-fluoroprop-1-ene, as well as the synthesis of 1,2-bis(2-fluoroallyl)disulfane, 5-fluoro-3-(1-fluorovinyl)-3,4-dihydro-1,2-dithiin, trifluoroajoene ((E,Z)-1-(2-fluoro-3-((2-fluoroallyl)sulfinyl)prop-1-en-1-yl)-2-(2-fluoroallyl)disulfane), and a bis(2-fluoroallyl)polysulfane mixture. All tested organosulfur compounds demonstrated effective inhibition of either FGF or VEG-mediated angiogenesis (anti-angiogenesis activity) in the chick chorioallantoic membrane (CAM) or the mouse Matrigel^® models. No embryo mortality was observed. Difluoroallicin demonstrated greater inhibition (p < 0.01) versus organosulfur compounds tested. Difluoroallicin demonstrated dose-dependent inhibition of angiogenesis in the mouse Matrigel^® model, with maximal inhibition at 0.01 mg/implant. Allicin and difluoroallicin showed an effective antiplatelet effect in suppressing platelet aggregation compared to other organosulfur compounds tested. In platelet/fibrin clotting (anti-coagulant activity), difluoroallicin showed concentration-dependent inhibition of clot strength compared to allicin and the other organosulfur compounds tested.

Elevated pretreatment platelet distribution width and platelet count predict poor prognosis in nasopharyngeal carcinoma

Background

Previous studies have demonstrated that platelets play a multifaceted role in cancer progression and metastasis. However, the value of platelet indices for predicting survival in nasopharyngeal carcinoma (NPC) patients remains unknown. The aim of this study was to evaluate the predictive significance of platelet indices in NPC cases.

Materials and Methods

A total of 168 patients who were diagnosed with NPC between January 2011 and June 2012 were recruited. The optimal cut-off values for the platelet indices were determined using a receiver operating characteristic curve. The Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of the potential predictors.

Results

Of the 168 patients, high platelet distribution width (PDW) and platelet count (PLT) levels were observed in 81 (48.21%) and 68 (40.48%) of the patients, respectively. An increased PDW was associated with the depth of invasion (T stage, P = 0.019), lymph node metastasis (N stage, P = 0.026), and clinical stage (P < 0.001). Moreover, the survival analysis showed that the overall survival of the patients with a PDW > 16.3 fL or platelet count > 266 × 10⁹/L was associated with a poorer prognosis (both P < 0.001). In the multivariate Cox regression model, the PDW (P < 0.001), PLT (P = 0.001), T stage (P < 0.001), N stage (P = 0.006), clinical stage (P = 0.005), and Epstein-Barr virus DNA (P = 0.039) were independent prognostic factors for the overall survival.

Conclusions

The PDW and PLT are easily available via a routine blood test, and our study showed that the PDW and PLT could be prognostic predictors in NPC patients. However, further studies are required to confirm this conclusion.

Elevated mean platelet volume predicts poor prognosis in colorectal cancer

Altered mean platelet volume (MPV) is implicated in several malignancies. However, the clinicopathological significance and prognostic value of MPV in colorectal cancer (CRC) is still elusive. The purpose of this study was to elucidate the predictive significance of MPV in CRC. The retrospective study recruited 509 consecutive CRC patients between January 2009 and December 2009. The relationships between MPV and clinicopathological characteristics were analyzed. Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of MPV. Of the 509 CRC patients, high MPV levels were detected in 150 (29.5%) patients. Elevated MPV was associated with tumor differentiation (p < 0.001). Patients with increased MPV had poor overall survival compared with those with normal level (60.0% vs. 83.6%, log-rank test, p = 0.035). Cox regression analysis showed that MPV was an independent prognostic factor in CRC (HR = 1.452, 95% CI = 1.118-1.884, p = 0.005). In conclusion, MPV is easily available in routine blood test. Elevated MPV might act as a marker of prognosis and therapeutic target for CRC.

Decreased mean platelet volume predicts poor prognosis in invasive bladder cancer

Background

Altered mean platelet volume (MPV) is implicated in a wide range of cancers. However, the prognostic role of MPV in muscle-invasive bladder cancer (MIBC) remains largely unknown. The purpose of this study was to elucidate the predictive significance of MPV in MIBC.

Method

The retrospective study included 218 consecutive MIBC patients between January 2009 and December 2009. The relationships between MPV and clinicopathological characteristics were analyzed. Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of MPV.

Result

Of the 218 patients, low MPV levels were detected in 141 (64.7 %) patients. Reduced MPV was associated with T stage and histology grade (p < 0.05). In the Kaplan-Meier analysis, decreased MPV was significantly associated with a poorer overall survival (p = 0.007). In the multivariate Cox model, decreased MPV was an independent prognostic index for overall survival (HR=2.023, 95% CI=1.050-3.897, p = 0.025).

Conclusion

MPV is easily available in routine blood test. Our results demonstrated that reduced MPV could be regarded as a potential prognosis indicator for clinical outcome in MIBC.

Increased platelet distribution width predicts poor prognosis in melanoma patients

Activated platelets promote cancer progression and metastasis. Nevertheless, the prognostic value of platelet indices in melanoma had been rarely reported. The aim of this study was to investigate the predictive significance of platelet indices in melanoma. A total of 220 consecutive patients with melanoma were retrospectively enrolled between January 2009 and December 2009. The relationship between PDW and clinicopathological characteristics were analyzed. Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of PDW. Of the 220 patients, high platelet distribution width (PDW) levels were observed in 63 (28.6%) patients. Increased PDW was associated with tumor subtype (P < 0.001). Survival curves found that patients with increased PDW had significantly shorter survival time than those with normal PDW (P < 0.001). Cox regression analysis revealed that elevated PDW was an independent prognostic factor for overall survival (hazard ratio, 2.480; 95% confidence interval [CI], 1.386–4.436, P = 0.002). In conclusion, PDW is easily available in routine blood test. Our findings indicated that PDW is an independent predictor and that it may also be a potential parameter for targeted therapy in melanoma.