Consensus statement on extracellular vesicles in liquid biopsy for advancing laboratory medicine.

Extracellular vesicles (EVs) represent a diverse class of nanoscale membrane vesicles actively released by cells. These EVs can be further subdivided into categories like exosomes and microvesicles, based on their origins, sizes, and physical attributes. Significantly, disease-derived EVs have been detected in virtually all types of body fluids, providing a comprehensive molecular profile of their cellular origins. As a result, EVs are emerging as a valuable addition to liquid biopsy techniques. In this collective statement, the authors share their current perspectives on EV-related research and product development, with a shared commitment to translating this newfound knowledge into clinical applications for cancer and other diseases, particularly as disease biomarkers. The consensus within this document revolves around the overarching recognition of the merits, unresolved questions, and existing challenges surrounding EVs. This consensus manuscript is a collaborative effort led by the Committee of Exosomes, Society of Tumor Markers, Chinese anti-Cancer Association, aimed at expediting the cultivation of robust scientific and clinically applicable breakthroughs and propelling the field forward with greater swiftness and efficacy.

Immunostimulant In Situ Fibrin Gel for Post-operative Glioblastoma Treatment by Macrophage Reprogramming and Photo-Chemo-Immunotherapy.

Tumor recurrence remains the leading cause of treatment failure following surgical resection of glioblastoma (GBM). M2-like tumor-associated macrophages (TAMs) infiltrating the tumor tissue promote tumor progression and seriously impair the efficacy of chemotherapy and immunotherapy. In addition, designing drugs capable of crossing the blood-brain barrier and eliciting the applicable organic response is an ambitious challenge. Here, we propose an injectable nanoparticle-hydrogel system that uses doxorubicin (DOX)-loaded mesoporous polydopamine (MPDA) nanoparticles encapsulated in M1 macrophage-derived nanovesicles (M1NVs) as effectors and fibrin hydrogels as in situ delivery vehicles. In vivo fluorescence imaging shows that the hydrogel system triggers photo-chemo-immunotherapy to destroy remaining tumor cells when delivered to the tumor cavity of a model of subtotal GBM resection. Concomitantly, the result of flow cytometry indicated that M1NVs comprehensively improved the immune microenvironment by reprogramming M2-like TAMs to M1-like TAMs. This hydrogel system combined with a near-infrared laser effectively promoted the continuous infiltration of T cells, restored T cell effector function, inhibited the infiltration of myeloid-derived suppressor cells and regulatory T cells, and thereby exhibited a strong antitumor immune response and significantly inhibited tumor growth. Hence, MPDA-DOX-NVs@Gel (MD-NVs@Gel) presents a unique clinical strategy for the treatment of GBM recurrence.

The Emerging Role of Exosomes in Cancer Chemoresistance.

Chemoresistance is an impending challenge in cancer treatment. In recent years, exosomes, a subtype of extracellular vesicles with a diameter of 40-150 nm in bloodstream and other bio-fluids, have attracted increasing interest. Exosomes contain proteins, nucleic acids, and lipids, which act as important signaling molecules. Many reports indicate that exosomes play critical roles in chemoresistance through intercellular interactions, including drug removal from cells, transfer of drug resistance phenotypes to other cancer cells, and the increase in plastic stem cell subsets. Exosomes can reflect the physiological and pathological state of parent cells. Owing to their elevated stability, specificity, and sensitivity, exosomes are served as biomarkers in liquid biopsies to monitor cancer chemoresistance, progression, and recurrence. This review summarizes the exosome-mediated mechanisms of cancer chemoresistance, as well as its role in reversing and monitoring chemoresistance. The scientific and technological challenges and future applications of exosomes are also explored.

THOC2 and THOC5 Regulate Stemness and Radioresistance in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Radioresistance and stemness are substantial obstacles to TNBC treatment. The THO complex (THOC) is a subunit of the TRanscription-EXport complex that functions in the coupling of transcription to nascent RNA splicing, elongation, and export. However, its role in regulating TNBC therapeutic resistance is not reported yet. In this study, the authors demonstrate that cancer stem cells are enriched in radioresistant TNBC cells and describe the role of the THOC in regulating TNBC radioresistance and stemness. The authors find that THOC2 and THOC5 are upregulated in radioresistant TNBC cells and associated with a poor prognosis in TNBC patients. Further investigation reveals that THOC2 promotes the stem-like properties and radioresistance of TNBC cells in a THOC5-dependent manner by facilitating the release of sex-determining region Y (SRY)-box transcription factor 2 (SOX2) and homeobox transcription factor (NANOG) transcripts from the nucleus. Silencing THOC2 or THOC5 expression decreases the protein expression of SOX2 and NANOG, depletes the stem-like properties, and causes radiosensitization in these TNBC cells. Moreover, THOC2 or THOC5 depletion blocks the xenograft tumorigenesis and growth of radioresistant TNBC in vivo. These findings uncover the novel correlations of THOC with TNBC stemness and therapeutic resistance, proposing alternative therapeutic strategies against relapsed TNBC.

Exosomes and breast cancer drug resistance.

Drug resistance is a daunting challenge in the treatment of breast cancer (BC). Exosomes, as intercellular communicative vectors in the tumor microenvironment, play an important role in BC progression. With the in-depth understanding of tumor heterogeneity, an emerging role of exosomes in drug resistance has attracted extensive attention. The functional proteins or non-coding RNAs contained in exosomes secreted from tumor and stromal cells mediate drug resistance by regulating drug efflux and metabolism, pro-survival signaling, epithelial-mesenchymal transition, stem-like property, and tumor microenvironmental remodeling. In this review, we summarize the underlying associations between exosomes and drug resistance of BC and discuss the unique biogenesis of exosomes, the change of exosome cargo, and the pattern of release by BC cells in response to drug treatment. Moreover, we propose exosome as a candidate biomarker in predicting and monitoring the therapeutic drug response of BC and as a potential target or carrier to reverse the drug resistance of BC.

PMLIV overexpression promotes TGF-ß-associated epithelial-mesenchymal transition and migration in MCF-7 cancer cells.

The epithelial-mesenchymal transition (EMT) is a key event associated with metastasis and dissemination in breast tumor pathogenesis. Promyelocytic leukemia (PML) gene produces several isoforms due to alternative splicing; however, the biological function of each specific isoform has yet to be identified. In this study, we report a previously unknown role for PMLIV, the most intensely studied nuclear isoform, in transforming growth factor-ß (TGF-ß) signaling-associated EMT and migration in breast cancer. This study demonstrates that PMLIV overexpression promotes a more aggressive mesenchymal phenotype and increases the migration of MCF-7 cancer cells. This event is associated with activation of the TGF-ß canonical signaling pathway through the induction of Smad2/3 phosphorylation and the translocation of phospho-Smad2/3 to the nucleus. In this study, we report a previously unknown role for PMLIV in TGF-ß signaling-induced regulation of breast cancer-associated EMT and migration. Targeting this pathway may be therapeutically beneficial.

SERPINA3 induced by astroglia/microglia co-culture facilitates glioblastoma stem-like cell invasion.

Glioblastoma (GBM) is a highly invasive and malignant brain tumor. Currently, it remains unclear whether Glioblastoma stem-like cells (GSCs) contribute to the invasive phenotype of GBM. Invasion is a complex process involving interactions between tumor cells with the extracellular matrix (ECM), in addition to normal cells. The present study aimed to identify the regulators of GSCs invasion in the GBM tumor microenvironment. An integrative analysis was conducted to identify genes that are important for GSC invasion and are specifically upregulated in astroglia/microglia co-cultured GSCs. Of the identified genes, serpin peptidase inhibitor clade A member 3 (SERPINA3) was observed to be abnormally overexpressed in astroglia/microglia co-cultured GSCs. To further investigate the role of SERPINA3 in glioma pathogenesis and prognosis, a tissue microarray analysis was conducted to evaluate the expression of SERPINA3 and its association to clinicopathological factors and patient survival. The data indicated that upregulation of SERPINA3 was significantly associated with glioma progression and poor patient survival. Furthermore, it was demonstrated that the upregulation of SERPINA3 in glioma may contribute to the invasive behavior of GBM cells by remodeling of the ECM. Overall, the findings of the present study may be useful in future prognosis of GBM patients, suggesting that SERPINA is a potential therapeutic target, and may lead to further understanding of GBM and cancer progression as a whole.

High Expression of Vimentin is Associated With Progression and a Poor Outcome in Glioblastoma.

Glioblastoma multiforme (GBM) has a high recurrence and mortality rate. Because of a poor understanding of the mechanism for this disease, treatment regimens have remained limited. Vimentin, one of the major cytoskeletal proteins, is associated with cellular structure. However, the function of vimentin in GBM is still undefined. In the present study, we investigated the expression level of vimentin in 179 GBM tissues using immunohistochemistry. We found that the vimentin expression level was associated with the time to progression (P=0.029). A Kaplan-Meier analysis revealed that patients with high vimentin expression had a significantly shorter overall survival (P=0.0002) and progression-free survival (P=0.0001) compared with those with low expression. Furthermore, in vitro experiments showed that withaferin-A, a chemical inhibitor of vimentin, could inhibit GBM cell migration and invasion activity when its concentrations were <0.5 µM, and higher concentrations of withaferin-A could decrease the viability of U251and U87 cells significantly. In conclusion, our results indicated that vimentin may play an important role in the progression of GBM.

Unexpected heat shock element binding ability and tumor-killing activity of the combinatorial function domain of apoptin.

Apoptin, derived from the chicken anemia virus, has been found to exert tumor-preferential apoptotic activity. It is a potential anticancer agent with direct clinical applications. However, if this viral protein were to be used as a new drug, it might also induce a strong immune response, causing toxic side effects. In a previous study, our group showed that TAT-apoptin downregulates the stress expression of heat shock protein 70 by competing with heat shock factor protein 1 in binding to the heat shock element (HSE) of the promoter region of heat shock protein 70, thus inducing specific apoptosis in HepG2 cells. In this study, we investigated the HSE-binding properties of the minimal functional region of apoptin. We showed that apoptin's nuclear localization signals 1 and nuclear localization signals 2 represented functional regions that could bind with HSE and that this binding capacity was increased by polymers formed through the introduction of a leucine-rich stretch. Our data also showed that truncated combinatorial apoptin peptide has greater tumor-specific cell-killing activity and could be a potential antitumor agent.

Chronic Moderate Alcohol Intakes Accelerate SR-B1 Mediated Reverse Cholesterol Transport.

Cholesterol is essential for all animal life. However, a high level of cholesterol in the body is strongly associated with the progression of various severe diseases. In our study, the potential involvement of alcohol in the regulation of high density lipoprotein (HDL) receptor scavenger receptor class B and type I (SR-B1)-mediated reverse cholesterol transport was investigated. We separated male C57BL/6 mice into four diets: control, alcohol, Control + HC and alcohol + HC. The SR-B1 level and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate- high- density lipoprotein (DiI-HDL) uptake were also measured in AML12 cells and HL7702 cells treated with alcohol. The control + HC diet led to increased hepatic triglyceride and cholesterol levels while alcohol + HC led no significant change. Compared with that of the control group, the SR-B1 mRNA level was elevated by 27.1% (P < 0.05), 123.8% (P < 0.001) and 343.6% (P < 0.001) in the alcohol, control + HC and alcohol + HC groups, respectively. In AML12 and HL7702 cells, SR-B1 level and DiI-HDL uptake were repressed by SR-B1 siRNA or GW9662. However, these effects were reversed through alcohol treatment. These data suggest that a moderate amount of alcohol plays a novel role in reverse cholesterol transport, mainly mediated by PPARγ and SR-B1.

Downregulation of TRAP1 sensitizes glioblastoma cells to temozolomide chemotherapy through regulating metabolic reprogramming.

Cancer cells preferentially use aerobic glycolysis to support growth, a metabolic alteration commonly referred to as the 'Warburg effect.' Here, we show that the tumor necrosis factor receptor-associated protein 1 (TRAP1) is crucial for the Warburg effect in human glioblastoma multiforme (GBM). In contrast to normal brain, GBMs show increased TRAP1 expression. We used both GBM cell lines and neurospheres derived from human GBM specimens to examine the effects of Knockdown of TRAP1 on GBM cell lines and glioma stem cells. We also used a neurosphere recovery assay that measured neurosphere formation at three time points to assess the capacity of the culture to repopulate after knockdown of TRAP1. Our results showed that knockdown of TRAP1 strongly decreased GBM cell proliferation and migration, inhibited neurosphere recovery, secondary neurosphere formation, and enhanced the therapeutic effect of temozolomide in neurosphere cultures. In GBM, knockdown of TRAP1 appeared to inhibit tumor growth and migration through its regulatory effects on metabolic reprogramming.

Type III TGF-ß receptor inhibits cell proliferation and migration in salivary glands adenoid cystic carcinoma by suppressing NF-κB signaling.

It is known that the TGF-ß superfamily receptors act as master regulators of cancer progression. However, alteration and role of type III TGF-ß receptor (TßRIII, or betaglycan) as the most abundant of the TGF-ß receptor has not been explored in salivary gland adenoid cystic carcinoma (ACC). Here, we reported that tumor biopsies and matched normal human salivary glands from patients with ACC were examined for the expression of TßRIII. The expression of TßRIII protein is significantly decreased in ACC patients based on immunohistochemistry and western blot analysis. In vitro, a transient overexpression of TßRIII markedly induced apoptosis and cell cycle arrest in the G2/M phase, thereby inhibited cell viability and migration of ACC-M cells. Co-immunoprecipitation revealed that TßRIII, scaffolding protein-arrestin2 (ß-arrestin2) and IκBα formed a complex. Transient overexpression of TßRIII decreased p-p65 expression and increased IκBα expression, which was abolished by knockdown of ß-arrestin2. The present study defines TßRIII as a biomarker exerting antitumor action on ACC progression.Gene therapy of TßRIII may be a powerful new approach for ACC disease.

Overexpression of transforming growth factor type III receptor restores TGF-ß1 sensitivity in human tongue squamous cell carcinoma cells.

The transforming growth factor type III receptor (TßRIII), also known as ß-glycan, is a multi-functional sensor that regulates growth, migration and apoptosis in most cancer cells. We hereby investigated the expression of TßRIII in clinical specimens of tongue squamous cell carcinoma (TSCC) and the underlying mechanism that TßRIII inhibits the growth of CAL-27 human oral squamous cells. The TSCC tissues showed a significant decrease in TßRIII protein expression as detected by immunohistochemistry (IHC) and western blot analysis. Transfection of TßRIII-containing plasmid DNA dramatically promoted TGF-ß1 (10 ng/ml)-induced decrease in cell viability, apoptosis and cell arrest at the G0-/G1-phase. Moreover, transient overexpression of TßRIII enhanced the TGF-ß1-induced cyclin-dependent kinase inhibitor 2b (CDKN2b) and p38 protein activity, but did not affect the activities of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase 1/2 (JNK1/2) in CAL-27 cells. These results suggest overexpression of TßRIII receptor restored TGF-ß1 sensitivity in CAL-27 cells, which may provide some new insights on exploiting this molecule therapeutically.

Downregulation of miR-21 is involved in direct actions of ursolic acid on the heart: implications for cardiac fibrosis and hypertrophy.

PURPOSE: Myocardial fibrosis contributes to cardiac remodeling and loss of cardiac function in myocardial infarction and heart failure. This study used in vitro and in vivo models to examine the effects of ursolic acid (UA) on myocardial fibrosis and to explore its potential mechanism. METHODS: Transverse aortic constriction (TAC) surgery was performed in mice to induce cardiac hypertrophy and fibrosis. UA was orally administered 1 week prior to TAC. Two weeks after TAC, myocardial pathology was detected using Masson's trichrome staining and transmission electron microscopy, and heart-to-body weight ratio was measured. For in vitro studies, cultured cardiac fibroblasts were treated with serum in the presence or absence of UA. The relative levels of miR-21 and p-ERK/ERK, collagen content and cell viability were measured. RESULTS: Ursolic acid attenuated pathological cardiac hypertrophy and myocardial fibrosis in vivo induced by TAC. Downregulation of miR-21 and p-ERK/ERK were observed in myocardial fibroblasts treated with UA in a dose-dependent manner compared with the control group both in vitro and in vivo. CONCLUSIONS: Our study demonstrates that UA can inhibit myocardial fibrosis both in vitro and in vivo, and the effects of UA on myocardial fibrosis may be due to the inhibition of miR-21/ERK signaling pathways.

Intraoperative fluorescence-guided resection of high-grade malignant gliomas using 5-aminolevulinic acid-induced porphyrins: a systematic review and meta-analysis of prospective studies.

BACKGROUND: We performed a systematic review and meta-analysis to address the (added) value of intraoperative 5-aminolevulinic acid (5-ALA)-guided resection of high-grade malignant gliomas compared with conventional neuronavigation-guided resection, with respect to diagnostic accuracy, extent of tumor resection, safety, and survival. METHODS AND FINDINGS: An electronic database search of Medline, Embase, and the Cochrane Library was undertaken. The review process followed the guidelines of the Cochrane Collaboration. 10 studies matched all selection criteria, and were thus used for qualitative synthesis. 5-ALA-guided resection demonstrated an overall sensitivity of 0.87 (95% confidence interval [CI], 0.81-0.92), specificity of 0.89 (95% CI, 0.79-0.94), positive likelihood ratio (LR) of 7.62 (95% CI, 3.87-15.01), negative LR of 0.14 (95% CI, 0.09-0.23), and diagnostic odds ratio (OR) of 53.06 (95% CI, 18.70-150.51). Summary receiver operating characteristic curves (SROC) showed an area under curve (AUC) of 94%. Contrast-enhancing tumor was completely resected in patients assigned 5-ALA as compared with patients assigned white light. Patients in the 5-ALA group had higher 6-month progression free survival and overall survival than those in the white light group. CONCLUSION: Based on available literature, there is level 2 evidence that 5-ALA-guided surgery is more effective than conventional neuronavigation-guided surgery in increasing diagnostic accuracy and extent of tumor resection, enhancing quality of life, or prolonging survival in patients with high-grade malignant gliomas.

Apoptin selectively induces the apoptosis of tumor cells by suppressing the transcription of HSP70.

Apoptin is a nonstructural viral protein encoded by VP3 gene of chicken anemia virus, which could specially induce apoptosis of tumor cells. However, the mechanism of apoptin-induced apoptosis in tumor cells without any side effects in normal cells has not yet been well characterized. This study aimed to investigate the molecular mechanism underlying the selective antitumor effects of apoptin. HepG2 cells were treated with apoptin or transfected with apoptin expression vector. Heat shock protein 70 (HSP70) expression was examined by Western blot. The binding of apoptin to HSP70 promoter was detected by electrophoretic mobility shift assay, chromatin immunoprecipitation, and luciferase assay. The results showed that apoptin inhibited HSP70 expression in HepG2 cells and apoptin-induced apoptosis of HepG2 cells was dependent on the expression level of HSP70. Furthermore, apoptin promoted HSF1 trimer depolymerization and inhibited HSF1-mediated HSP70 transcription. In addition, apoptin competed with HSF1 to bind heat shock element in HSP70 promoter, leading to reduced HSP70 transcription. Both these mechanisms contribute to the suppression of HSP70 transcription and expression. Our findings provide the first evidence that apoptin induces tumor cell apoptosis by specifically downregulating the expression of HSP70, which helps explain the specific antitumor effects of apoptin.

Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer: a meta-analysis.

BACKGROUND AND AIMS: Case/control studies that investigated the association between gastric cancer and the MTHFR C677T and A1298C polymorphisms so far have provided controversial results. To clarify the effect of MTHFR polymorphisms on the risk of gastric cancer, a meta-analysis was performed. METHODS: We performed a computerized search of the PubMed database for relevant reports before September 2009. No language restrictions were added. The associated literature was acquired through a deliberate retrieval strategy and selected based on the established inclusion criteria for publications. RESULTS: The studies provided 4070/6462 cases/controls for C677T and 1923/3561 cases/controls for A1298C. There was significant heterogeneity (p = 0.015, I(2) = 44.0%) among the 22 studies, and the RE model showed that the C677T allele T was associated with a 17.3% increased risk of gastric cancer compared with the allele C (RE OR = 1.173 [1.051-1.274]). Results from the subgroup analysis showed an increased risk in Asians (fixed-effect, FE OR 1.277 [1.179-1.382]), but not in Caucasians (random-effect, RE OR 1.194 [0.866-1.646]). The contrast of homozygotes (TT vs. CC) produced significant results in Asians (FE OR 1.611 [1.366-1.901]), whereas, in Caucasians, it was not significant (RE OR 1.385 [0.754-2.544]). In regard to the A1298C polymorphism, there was no heterogeneity among the 11 studies comparing the C vs. the A allele (p = 0.352, I(2) = 9.7%), but no significant association was detected. CONCLUSIONS: The evidence from our meta-analysis supports that TT genotype of MTHFR C677T polymorphism contributes to susceptibility to gastric cancer, but no significant association was detected for CC genotype of MTHFR A1298C.