Vimentin and Ki67 expression in circulating tumour cells derived from castrate-resistant prostate cancer

MKI67 with arterial hypertension predict a poor survival for prostate cancer patients, a real-life investigation

INTRODUCTION

Prostate cancer is a common urology malignant in males, ranking second globally. The disease is especially severe when diagnosed alongside hypertension. MKI67 is an established marker of neoplastic cell proliferation in humans, but the significance of its prognostic value in patients with prostate cancer and hypertension requires further research.

METHODS

In this retrospective analysis, we evaluated 296 hypertensive prostate cancer patients between March 2, 2012, and November 1, 2015. We used Cox regression models and prediction analysis to assess overall survival. Furthermore, we created a nomogram and verified its accuracy using a calibration curve.

RESULTS

Of all participants, 101 (34.12%) died. Our multi-factor analysis revealed that MKI67 expression was associated with an increased hazard ratio of death (> fivefold) (Hazard Ratio 5.829, 95% CI 3.349-10.138, p value < 0.01) and progression (twofold) (HR 2.059, 95% CI 1.368-3.102, p value < 0.01). Our Lasso analysis model displayed that several factors, including heart failure, smoking, ACS, serum albumin, Gealson score, prognostic nutritional index, MKI67 expression, surgery, and stage were high risks of prostate cancer. To ensure each covariate's contribution to cancer prognosis, we created a Cox model nomogram, which accurately predicted the risk of death (C-statistic of 0.8289) and had a proper calibration plot for risk assessment.

CONCLUSION

MKI67 expression predicts poor outcomes for overall mortality in prostate cancer and hypertension patients. Additionally, our cross-validated multivariate score, which includes MKI67, demonstrated accuracy efficacy of predicting prognosis.

Identification of functional and diverse circulating cancer-associated fibroblasts in metastatic castration-naïve prostate cancer patients

In prostate cancer (PCa), cancer-associated fibroblasts (CAFs) promote tumor progression, drug resistance, and metastasis. Although circulating tumor cells are studied as prognostic and diagnostic markers, little is known about other circulating cells and their association with PCa metastasis. Here, we explored the presence of circulating CAFs (cCAFs) in metastatic castration-naïve prostate cancer (mCNPC) patients. cCAFs were stained with fibroblast activation protein (FAP), epithelial cell adhesion molecule (EpCAM), and receptor-type tyrosine-protein phosphatase C (CD45), then FAP+EpCAM- cCAFs were enumerated and sorted using fluorescence-activated cell sorting. FAP+EpCAM- cCAFs ranged from 60 to 776 (389 mean ± 229 SD) per 2 × 108 mononuclear cells, whereas, in healthy donors, FAP+ EpCAM- cCAFs ranged from 0 to 71 (28 mean ± 22 SD). The mCNPC-derived cCAFs showed positivity for vimentin and intracellular collagen-I. They were viable and functional after sorting, as confirmed by single-cell collagen-I secretion after 48 h of culturing. Two cCAF subpopulations, FAP+CD45- and FAP+CD45+, were identified, both expressing collagen-I and vimentin, but with distinctly different morphologies. Collectively, this study demonstrates the presence of functional and viable circulating CAFs in mCNPC patients, suggesting the role of these cells in prostate cancer.

Marker Ki-67 is a potential biomarker for the diagnosis and prognosis of prostate cancer based on two cohorts

BACKGROUND

Prostate cancer (PCa) is a widespread malignancy, predominantly affecting elderly males, and current methods for diagnosis and treatment of this disease continue to fall short. The marker Ki-67 (MKI67) has been previously demonstrated to correlate with the proliferation and metastasis of various cancer cells, including those of PCa. Hence, verifying the association between MKI67 and the diagnosis and prognosis of PCa, using bioinformatics databases and clinical data analysis, carries significant clinical implications.

AIM

To explore the diagnostic and prognostic efficacy of antigens identified by MKI67 expression in PCa.

METHODS

For cohort 1, the efficacy of MKI67 diagnosis was evaluated using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. For cohort 2, the diagnostic and prognostic power of MKI67 expression was further validated using data from 271 patients with clinical PCa.

RESULTS

In cohort 1, MKI67 expression was correlated with prostate-specific antigen (PSA), Gleason Score, T stage, and N stage. The receiver operating characteristic (ROC) curve showed a strong diagnostic ability, and the Kaplan-Meier method demonstrated that MKI67 expression was negatively associated with the progression-free interval (PFI). The time-ROC curve displayed a weak prognostic capability for MKI67 expression in PCa. In cohort 2, MKI67 expression was significantly related to the Gleason Score, T stage, and N stage; however, it was negatively associated with the PFI. The time-ROC curve revealed the stronger prognostic capability of MKI67 in patients with PCa. Multivariate COX regression analysis was performed to select risk factors, including PSA level, N stage, and MKI67 expression. A nomogram was established to predict the 3-year PFI.

CONCLUSION

MKI67 expression was positively associated with the Gleason Score, T stage, and N stage and showed a strong diagnostic and prognostic ability in PCa.

OCT4‑positive circulating tumor cells may predict a poor prognosis in patients with metastatic castration‑resistant prostate cancer treated with abiraterone plus prednisone therapy

Octamer-binding transcription factor 4 (OCT4) and circulating tumor cells (CTCs) are key factors associated with tumor metastasis and drug resistance in cancer. The present prospective study aimed to investigate the prevalence of OCT4-positive (OCT4+) CTCs and the potential association with the clinical features and survival of patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone + prednisone. In total, 70 patients with mCRPC treated with abiraterone + prednisone were enrolled in the present study and peripheral blood samples were collected prior to treatment initiation to determine CTC count via a Canpatrol system. RNA in situ hybridization was performed for OCT4+ CTC quantification. Lactate dehydrogenase (LDH) was detected by automatic biochemical analyzer (AU54000, OLYMPUS). Results demonstrated that 34 (48.6%), 21 (30.0%) and 15 (21.4%) patients harbored OCT4+ (CTC+/OCT4+) or OCT4-negative CTCs (CTC+/OCT4-) or were CTC-negative (CTC-), respectively. Notably, CTC+/OCT4+ occurrence was associated with visceral metastasis and high levels of LDH. In addition, radiographic progression-free survival [rPFS; median, 15.0, 95% confidence interval (CI), 9.6-20.4 vs. not reached vs. median, 29.5, 95% CI, 18.6-40.4 months; P=0.001] and overall survival (OS) were significantly decreased (median, 27.3, 95% CI, 20.1-34.5 vs. not reached vs. not reached; P=0.016) in CTC+/OCT4+ compared with CTC+/OCT4- and CTC- patients. Subsequently, the adjustment was performed by multivariate Cox regression models, which revealed that CTC+/OCT4+ (vs. CTC+/OCT4- or CTC-) was independently associated with decreased rPFS [hazard ratio (HR), 3.833; P<0.001] and OS (HR, 3.938; P=0.008). In conclusion, OCT4+ CTCs were highly prevalent in patients with mCRPC and associated with visceral metastasis and increased levels of LDH. Thus, the presence of OCT4+ CTCs may serve as an independent prognostic factor for patients with mCRPC treated with abiraterone + prednisone.

Prognostic Role of Circulating Tumor Cells in Patients with Metastatic Castration-Resistant Prostate Cancer Receiving Cabazitaxel: A Prospective Biomarker Study

RATIONAL

Circulating tumor cells (CTCs) appear to be a promising tool for predicting the clinical outcome and monitoring the response to treatment in patients with solid tumors. The current study assessed the clinical relevance of monitoring CTCs in patients with metastatic castration resistant prostate cancer (mCRPC) treated with cabazitaxel.

PATIENTS AND METHODS

Patients with histologically confirmed mCRPC who were previously treated with a docetaxel-containing regimen and experienced disease progression were enrolled in this multicenter prospective study. CTC counts were enumerated using the CellSearch system at baseline (before cabazitaxel initiation), after one cabazitaxel cycle (post 1st cycle) and at disease progression (PD). Patients were stratified into predetermined CTC-positive and CTC-negative groups. The phenotypic characterization was performed using double immunofluorescence staining with anti-CKs and anti-Ki67, anti-M30 or anti-vimentin antibodies.

RESULTS

The median PFS and OS were 4.0 (range, 1.0-17.9) and 14.5 (range, 1.2-33.9) months, respectively. At baseline, 48 out of 57 (84.2%) patients had ≥1 CTCs/7.5 mL of peripheral blood (PB) and 37 (64.9%) had ≥5 CTCs/7.5 mL of PB. After one treatment cycle, 30 (75%) out of the 40 patients with available measurements had ≥1 detectable CTC/7.5 mL of PB and 24 (60%) ≥ 5CTCs/7.5 mL of PB; 12.5% of the patients with detectable CTCs at the baseline sample had no detectable CTCs after one treatment cycle. The detection of ≥5CTCs/7.5 mL of PB at baseline and post-cycle 1 was associated with shorter PFS and OS (p = 0.002), whereas a positive CTC status post-cycle 1 strongly correlated with poorer OS irrespective of the CTC cut-off used. Multivariate analysis revealed that the detection of non-apoptotic (CK+/M30-) CTCs at baseline is an independent predictor of shorter OS (p = 0.005).

CONCLUSIONS

In patients with mCRPC treated with cabazitaxel, CTC counts both at baseline and after the first cycle retain their prognostic significance, implying that liquid biopsy monitoring might serve as a valuable tool for predicting treatment efficacy and survival outcomes.

Can we use Ki67 expression to predict prostate cancer aggressiveness?

INTRODUCTION

specialists have an urge for biomarkers that can discriminate indolent prostate cancer from aggressive tumors. Ki67 is a proliferation marker, and its expression is associated with the aggressiveness of several cancers.

OBJECTIVE

analyze the expression of Ki67 in prostate cancer samples correlating with the aggressiveness of the disease.

METHODS

Ki67 mRNA levels were determined utilizing data from a TCGA cohort (Tumor(n)=492 and control(n)=52). The protein expression was determined on 94 biopsies from patients by immunohistochemical assay.

RESULTS

in mRNA, the Ki67 upregulation is associated with cancer tissue (p<0.0001) and worst disease-free survival (p=0.035). The protein upregulation is associated with increase of the ISUP score (p<0.0001), cancer stage (p=0.05), biochemical recurrence (p=0.0006) and metastasis (p<0.0001). We also show a positive correlation between Ki67 expression and ISUP score (r=0.5112, p<0.0001) and disease risk stratification (r=0.3388, p=0.0009). Ki67 expression is a factor independently associated with biochemical recurrence (p=0.002) and metastasis (p<0.0001). Finally, the patients with high Ki67expression shows better survival regarding biochemical recurrence (p=0.008) and metastasis (p=0.056). Patients with high Ki67 expression are 2.62 times more likely to develop biochemical recurrence (p=0.036).

CONCLUSION

Ki67 upregulation is associated with prostate cancer aggressiveness.

The crossroads of adenosinergic pathway and epithelial-mesenchymal plasticity in cancer

Epithelial-mesenchymal transition (EMT) is a key mechanism related to tumor progression, invasion, metastasis, resistance to therapy and poor prognosis in several types of cancer. However, targeting EMT or partial-EMT, as well as the molecules involved in this process, has remained a challenge. Recently, the CD73 enzyme, which hydrolyzes AMP to produce adenosine (ADO), has been linked to the EMT process. This relationship is not only due to the production of the immunosuppressant ADO but also to its role as a receptor for extracellular matrix proteins, being involved in cell adhesion and migration. This article reviews the crosstalk between the adenosinergic pathway and the EMT program and the impact of this interrelation on cancer development and progression. An in silico analysis of RNAseq datasets showed that several tumor types have a significant correlation between an EMT score and NT5E (CD73) and ENTPD1 (CD39) expressions, with the strongest correlations in prostate adenocarcinoma. Furthermore, it is evident that the cooperation between EMT and adenosinergic pathway in tumor progression is context and tumor-dependent. The increased knowledge about this topic will help broaden the view to explore new treatments and therapies for different types of cancer.

Correlation between the Expression of VEGF and Ki67 and Lymph Node Metastasis in Non-small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

Lymph node metastasis is the most common and important way of metastasis in NSCLC and is also the most important factor affecting lung cancer stage and prognosis. It is very important to analyze the relationship between the expression of vascular endothelial growth factor (VEGF) and Ki67 and lymph node metastasis (LNM) in non-small-cell lung cancer (NSCLC).

Methods

We searched the PubMed, EMBASE, and Cochrane Library and conducted meta-analyses using the R meta-package. Relative risk (RR) with a 95% confidence interval (95% CI) was the main indicator.

Results

Totally, 18 studies were considered eligible, with 4521 patients, including 1518 LNM-positive patients and 3033 LNM-negative patients. The incidence of LNM in Ki67-negative patients was lower than that in Ki67-positive patients (RR = 0.66, 95% CI: 0.44, 0.98). The incidence of LNM in VEGF-A-negative patients was lower than that in VEGF-A-positive patients (RR = 0.64, 95% CI: 0.49, 0.83). The incidence of LNM in VEGF-C negative patients was lower than that in VEGF-C positive patients (RR = 0.68, 95% CI: 0.53, 0.88). The incidence of LNM in VEGF-D negative and positive patients were of no significant differences (RR = 0.84, 95% CI: 0.61, 1.14).

Conclusion

The high expression of Ki67, VEGF-A, and VEGF-C significantly increases the risk of lymph node metastasis in NSCLC, while the VEGF-D expression has no correlation with lymph node metastasis. The expression levels of Ki67, VEGF-A, and VEGF-C show a good potential for lymph node metastasis prediction.

Application of circulating tumour cells to predict response to treatment in head and neck cancer

Background

Local recurrence and metastasis remain the major causes of death in head and neck cancer (HNC) patients. Circulating tumour cells (CTCs) are shed from primary and metastatic sites into the circulation system and have been reported to play critical roles in the metastasis and recurrence of HNC. Here, we explored the use of CTCs to predict the response to treatment and disease progression in HNC patients.

Methods

Blood samples were collected at diagnosis from HNC patients (n = 119). CTCs were isolated using a spiral microfluidic device and were identified using immunofluorescence staining. Correlation of baseline CTC numbers to 13-week PET-CT data and multidisciplinary team consensus data were conducted.

Results

CTCs were detected in 60/119 (50.4%) of treatment naïve HNC patients at diagnosis. Baseline CTC numbers were higher in stage III vs. stage I-II p16-positive oropharyngeal cancers (OPCs) and other HNCs (p = 0.0143 and 0.032, respectively). In addition, we found that baseline CTC numbers may serve as independent predictors of treatment response, even after adjusting for other conventional prognostic factors. CTCs were detected in 10 out of 11 patients exhibiting incomplete treatment responses.

Conclusions

We found that baseline CTC numbers are correlated with treatment response in patients with HNC. The expression level of cell-surface vimentin (CSV) on CTCs was significantly higher in patients with persistent or progressive disease, thus providing additional prognostic information for stratifying the risk at diagnosis in HNC patients. The ability to detect CTCs at diagnosis allows more accurate risk stratification, which in the future may be translated into better patient selection for treatment intensification and/or de-intensification strategies.

Supplementary information

The online version contains supplementary material available at 10.1007/s13402-022-00681-w.

Identification of epithelial and mesenchymal circulating tumor cells in clonal lineage of an aggressive prostate cancer case

Little is known about the complexity and plasticity of circulating tumor cell (CTC) biology in different compartments of the fluid microenvironment during tumor metastasis. Here we integrated phenomics, genomics, and targeted proteomics to characterize CTC phenotypic and genotypic heterogeneity in paired peripheral blood (PB) and bone marrow aspirate (BMA) from a metastatic prostate cancer patient following the rapid disease progression, using the High-Definition Single Cell Assay 3.0 (HDSCA3.0). Uniquely, we identified a subgroup of genetically clonal CTCs that acquired a mesenchymal-like state and its presence was significantly associated with one subclone that emerged along the clonal lineage. Higher CTC abundance and phenotypic diversity were observed in the BMA than PB and differences in genomic alterations were also identified between the two compartments demonstrating spatial heterogeneity. Single cell copy number profiling further detected clonal heterogeneity within clusters of CTCs (also known as microemboli or aggregates) as well as phenotypic variations by targeted proteomics. Overall, these results identify epithelial and mesenchymal CTCs in the clonal lineage of an aggressive prostate cancer case and also demonstrate a single cell multi-omic approach to deconvolute the heterogeneity and association of CTC phenotype and genotype in multi-medium liquid biopsies of metastatic prostate cancer.

Detyrosinated α-Tubulin, Vimentin and PD-L1 in Circulating Tumor Cells (CTCs) Isolated from Non-Small Cell Lung Cancer (NSCLC) Patients

Upregulation of Vimentin (VIM), alpha-Tubulin (TUB) and Detyrosinated tubulin (GLU) in circulating tumor cells (CTCs) derived from breast cancer patients is related to poor prognosis. In the current study we evaluated for the first time, these cytoskeletal proteins in sixty Non-Small Cell Lung Cancer (NSCLC) patients’ CTCs (33 treatment-naïve and 27 pre-treated). Samples were isolated using the ISET platform and stained with a pancytokeratin (CK)/CD45/TUB, CK/GLU/VIM and CK/programmed death ligand 1 (PD-L1) combination of antibodies. Subsequently, slides were analyzed using confocal laser scanning microscopy. CTCs were detected in 86.7% of the patients. CTCs with TUB expression were identified in 65.4% (34/52) of the CK (+)-patients. GLU, VIM and PD-L1 were also evaluated. The frequency of the observed phenotypes was as follow: (CK+/GLU−/VIM−): 35.2%, (CK+/GLU+/VIM+): 63.0%, (CK+/GLU+/VIM−): 16.7%, (CK+/GLU−/VIM+): 72.2%, (CK+/PD-L1−): 75% and (CK+/PD-L1+): 55%. The OS was significantly decreased in patients with high GLU (3.8 vs. 7.9 months; p = 0.018) and/or high VIM (3.2 vs. 7.1 months; p = 0.029) expression in their CTCs. PD-L1 was also related to OS (3.4 vs. 7.21 months; p = 0.035). Moreover, TUB-high and TUB-low expression in CTCs inversely influenced patients’ OS as independent prognostic factors (p = 0.041 and p = 0.009). The current study revealed that TUB, GLU, VIM and PD-L1 were overexpressed in CTCs from NSCLC patients. Furthermore, the presence of GLU, VIM-positive and PD-L1 in CTCs is potentially related to patients’ outcomes.

Podemos usar a expressão de Ki67 para prever a agressividade do câncer de próstata?

RESUMO Introdução: especialistas precisam biomarcadores que podem discriminar o câncer de próstata indolente de tumores agressivos. Ki67 é um marcador de proliferação, e sua expressão está associada à agressividade de vários tumores. Objetivo: analisar a expressão do Ki67 em amostras de câncer de próstata correlacionando com a agressividade da doença. Métodos: os níveis de mRNA de Ki67 foram determinados utilizando dados de uma coorte de TCGA (Tumor(n)=492 e controle(n)=52). A expressão da proteína foi determinada em 94 biópsias de pacientes por ensaio imuno-histoquímica. Resultados: no mRNA, a superexpressão Ki67 está associada ao tecido canceroso (p<0,0001) e à pior sobrevida livre de doença (p=0,035). A superexpressão proteica está associada ao aumento do escore ISUP (p<0,0001), estágio de câncer (p=0,05), recorrência bioquímica (p=0,0006) e metástase (p<0,0001). Também mostramos uma correlação positiva entre a expressão Ki67 e o escore ISUP (r=0,5112, p<0,0001) e a estratificação de risco de doença (r=0,3388, p=0,0009). A expressão Ki67 é um fator independentemente associado à recorrência bioquímica (p=0,002) e metástase (p<0,0001). Finalmente, os pacientes com alta expressão de Ki67 expression mostram melhor sobrevivência em relação à recorrência bioquímica (p=0,008) e metástase (p=0,056). Os pacientes com alta expressão de Ki67 são 2,62 vezes mais propensos a desenvolver recorrência bioquímica (p=0,036). Conclusão: a superexpressão Ki67 está associada à agressividade do câncer de próstata.

Multi-Marker Immunofluorescent Staining and PD-L1 Detection on Circulating Tumour Cells from Ovarian Cancer Patients

Simple Summary

Circulating tumour cells (CTCs) have the potential to serve as a rich source of information for cancer diagnostic and therapeutic decisions. To fully exploit this minimally invasive diagnostic resource requires techniques that aid in enriching heterogenous populations of CTCs and markers to efficiently characterise these cells as tumour derived. In the present study we eva-luated the microfluidic enrichment of CTCs and a multi-marker staining methodology for the identification of heterogeneous CTCs in ovarian cancer (OC) patients and evaluation of PD-L1 expression. We showed, for the first time, the existence of hybrid CTCs with an epithelial/mesenchymal phenotype and their association with PD-L1 in OC. Incorporation of this method in future clinical trials can help predict immunotherapy responsiveness in OC patients.

Abstract

Detection of ovarian cancer (OC) circulating tumour cells (CTCs) is primarily based on targeting epithelial markers, thus failing to detect mesenchymal tumour cells. More importantly, the immune checkpoint inhibitor marker PD-L1 has not been demonstrated on CTCs from OC patients. An antibody staining protocol was developed and tested using SKOV-3 and OVCA432 OC cell lines. We targeted epithelial (cytokeratin (CK) and EpCAM), mesenchymal (vimentin), and OC-specific (PAX8) markers for detection of CTCs, and CD45/16 and CD31 were used for the exclusion of white blood and vascular endothelial cells, respectively. PD-L1 was used for CTC characterisation. CTCs were enriched using the Parsortix™ system from 16 OC patients. Results revealed the presence of CTCs in 10 (63%) cases. CTCs were heterogeneous, with 113/157 (72%) cells positive for CK/EpCAM (epithelial marker), 58/157 (37%) positive for vimentin (mesenchymal marker), and 17/157 (11%) for both (hybrid). PAX8 was only found in 11/157 (7%) CTCs. In addition, 62/157 (39%) CTCs were positive for PD-L1. Positivity for PD-L1 was significantly associated with the hybrid phenotype when compared with the epithelial (p = 0.007) and mesenchymal (p = 0.0009) expressing CTCs. Characterisation of CTC phenotypes in relation to clinical outcomes is needed to provide insight into the role that epithelial to mesenchymal plasticity plays in OC and its relationship with PD-L1.

Role of aneuploid circulating tumor cells and CD31+ circulating tumor endothelial cells in predicting and monitoring anti-angiogenic therapy efficacy in advanced NSCLC

Prognosticating the efficacy of anti‐angiogenic therapy through longitudinal monitoring and early detection of treatment resistance in cancer patients remain highly challenging. In this study, co‐detection and comprehensive phenotypic and karyotypic molecular characterization of aneuploid circulating tumor cells (CTCs) and circulating tumor endothelial cells (CTECs) were conducted on non‐small cell lung cancer (NSCLC) patients receiving bevacizumab plus chemotherapy. Prognostic values of the cell‐based significant univariate risk factors identified by Cox regression analyses were progressively investigated. Subjects showing an increase in total post‐therapeutic platelet endothelial cell adhesion molecule‐1 (CD31)^– CTCs and CD31⁺ CTECs exhibited a significantly reduced median progression‐free survival (mPFS) and overall survival. Further stratification analyses indicated that pretherapeutic patients bearing vimentin (Vim)⁺ CTECs (mesenchymal M‐type) at baseline revealed a significantly shortened mPFS compared with patients with Vim^– CTECs. Post‐therapeutic patients harboring epithelial cell adhesion molecule (EpCAM)⁺ CTCs and CTECs (epithelial E‐type), regardless of Vim expression or not, showed a significantly reduced mPFS. Post‐therapeutic patients possessing de novo EpCAM⁺/Vim⁺ (hybrid E/M‐type) CTECs displayed the shortest mPFS. Patients harboring either pre‐ or post‐therapeutic EpCAM^–/Vim^– null CTECs (N‐type) exhibited a better response to therapy compared to patients harboring EpCAM⁺ and/or Vim⁺ CTECs. The presented results support the notion that baseline Vim⁺ CTECs and post‐therapeutic EpCAM⁺ CTCs and CTECs are predictive biomarkers for longitudinal monitoring of response to anti‐angiogenesis combination regimens in NSCLC patients.

Clinical significance of circulating tumour cells and Ki-67 in renal cell carcinoma

Background

Renal cell carcinoma (RCC) is a common malignant tumour of the genitourinary system. We aimed to analyse the potential value of metastasis-related biomarkers, circulating tumour cells (CTCs) and the proliferative marker Ki-67 in the diagnosis of RCC.

Methods

Data from 24 laparoscopic radical nephrectomies (RNs) and 17 laparoscopic partial nephrectomies (PNs) were collected in 2018. The numbers and positive rates of CTCs and circulating tumour microemboli (CTM) in the peripheral blood were obtained at three different time points: just before surgery, immediately after surgery and 1 week after surgery. Ki-67 protein expression was evaluated in the RCC tissue by immunohistochemistry.

Results

Except for the statistically significant association between the preoperative CTC counts and tumour size, no association between the number and positive rate of perioperative CTCs and clinicopathological features was found. The CTC counts gradually decreased during the perioperative period, and at 1 week after surgery, they were significantly lower than those before surgery. High Ki-67 expression was significantly positively correlated with preoperative CTC counts. In addition, Ki-67 expression was higher in the high CTC group (≥ 5 CTCs).

Conclusion

Our results suggest that surgical nephrectomy is associated with a decrease in CTC counts in RCC patients. CTCs can act as a potential biomarker for the diagnosis and prognosis of RCC. A careful and sufficient long-term follow-up is needed for patients with high preoperative CTC counts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02268-5.

Overexpression of Stat3 increases circulating cfDNA in breast cancer

PURPOSE

Current studies on circulating cell-free DNA (cfDNA) have been focusing on its potential as biomarkers in liquid biopsy by detecting its content or genetic and epigenetic changes for the evaluation of tumor burden and therapeutic efficacy. However, the regulatory mechanism of cfDNA release remains unclear. Stat3 has been documented as an oncogene for the development and metastasis of breast cancer cells. In this study, we investigated whether Stat3 affects the release of cfDNA into blood and its association with the number of circulating tumor cells (CTCs).

METHODS

The cfDNA level in plasma of patients with breast cancer and healthy volunteers were determined by quantitative real-time PCR. Three mouse breast cancer models with different Stat3 expression were generated and used to established three breast cancer orthotopic animal models to examine the effect of Stat3 on cfDNA release in vivo. Stat3 mediated Epithelial-mesenchymal phenotype transition of CTCs was determined by immunofluorescence assay and Western blot assay.

RESULTS

The data showed that Stat3 increased circulating cfDNA, which is correlated with the increased volume of primary tumors and number of CTCs, accompanied with the dynamic EMT changes regulated by Snail induction. Furthermore, the high level of total circulating cfDNA and Stat3-cfDNA in patients with breast cancer were detected by quantitative real-time PCR using GAPDH and Stat3 primers.

CONCLUSION

Our results suggested that Stat3 increases the circulating cfDNA and CTCs in breast cancer.

EMT-independent detection of circulating tumor cells in human blood samples and pre-clinical mouse models of metastasis

Circulating tumor cells (CTCs) present an opportunity to detect/monitor metastasis throughout disease progression. The CellSearch® is currently the only FDA-approved technology for CTC detection in patients. The main limitation of this system is its reliance on epithelial markers for CTC isolation/enumeration, which reduces its ability to detect more aggressive mesenchymal CTCs that are generated during metastasis via epithelial-to-mesenchymal transition (EMT). This Technical Note describes and validates two EMT-independent CTC analysis protocols; one for human samples using Parsortix® and one for mouse samples using VyCap. Parsortix® identifies significantly more mesenchymal human CTCs compared to the clinical CellSearch® test, and VyCap identifies significantly more CTCs compared to our mouse CellSearch® protocol regardless of EMT status. Recovery and downstream molecular characterization of CTCs is highly feasible using both Parsortix® and VyCap. The described CTC protocols can be used by investigators to study CTC generation, EMT and metastasis in both pre-clinical models and clinical samples.

Mesenchymal Characteristics and Predictive Biomarkers on Circulating Tumor Cells for Therapeutic Strategy

Metastasis-related events are the primary cause of cancer-related deaths, and circulating tumor cells (CTCs) have a pivotal role in metastatic relapse. CTCs include a variety of subtypes with different functional characteristics. Interestingly, the epithelial-mesenchymal transition (EMT) markers expressed in CTCs are strongly associated with poor clinical outcome and related to the acquisition of circulating tumor stem cell (CTSC) features. Recent studies have revealed the existence of CTC clusters, also called circulating tumor microemboli (CTM), which have a high metastatic potential. In this review, we present current opinions regarding the clinical significance of CTCs and CTM with a mesenchymal phenotype as clinical surrogate markers, and we summarize the therapeutic strategy according to phenotype characterization of CTCs in various types of cancers for future precision medicine.

Circulating tumor cell enumeration for improved screening and disease detection of patients with colorectal cancer

Background

The immunochemical fecal occult blood test (iFOBT) for colorectal cancer (CRC) screening and the serum carcinoembryonic antigen (CEA) assay for disease detection of CRC is associated with a high false-positive rate and a low detection sensitivity, respectively. There is an unmet need to define additional modalities to complement these assays. Different subsets of circulating tumor cells (CTCs) are present in the peripheral blood of cancer patients. Whether or not CTCs testing supplements these clinical assays and is valuable for patients with CRC was investigated.

Methods

CTCs were enriched from pre-operative patients with CRC (n = 109) and the non-cancerous controls (n = 65). CTCs expressing either epithelial cell adhesion molecule (EpCAM) or podoplanin (PDPN, the marker associated with poor cancer prognosis) were defined by immunofluorescence staining and were analyzed alone or in combination with iFOBT or serum CEA.

Results

Patients with early or advanced stage of CRC can be clearly identified and differentiated from the non-cancerous controls (p < 0.001) by EpCAM⁺-CTC or PDPN⁺-CTC count. The sensitivity and specificity of EpCAM⁺-CTCs was 85.3% and 78.5%, respectively, when the cutoff value was 23 EpCAM⁺-CTCs/mL of blood; and the sensitivity and specificity of PDPN⁺-CTCs was 78.0% and 75.4%, respectively, when the cutoff value was 7 PDPN⁺-CTCs/mL of blood. Combined analysis of iFOBT with the EpCAM⁺-CTC and PDPN⁺-CTC count reduced the false-positive rate of iFOBT from 56.3% to 18.8% and 23.4%, respectively. Combined analysis of serum CEA with the EpCAM⁺-CTC and PDPN⁺-CTC count increased the disease detection rate from 30.3% to 89.9% and 86.2%, respectively.

Conclusion

CTC testing could supplement iFOBT to improve CRC screening and supplement serum CEA assay for better disease detection of patients with CRC.

Genome-wide gene expression analysis of a murine model of prostate cancer progression: Deciphering the roles of IL-6 and p38 MAPK as potential therapeutic targets

BACKGROUND

Prostate cancer (PCa) is the most commonly diagnosed cancer and the second leading cause of cancer-related deaths among adult males globally. The poor prognosis of PCa is largely due to late diagnosis of the disease when it has already progressed to an advanced stage marked by androgen-independence, thus necessitating new strategies for early detection and treatment. We construe that these direly needed advances are limited by our poor understanding of early events in the progression of PCa and that would thus represent ideal targets for early intervention. To begin to fill this void, we interrogated molecular "oncophenotypes" that embody the transition of PCa from an androgen-dependent (AD) to-independent (AI) state.

METHODS

To accomplish this aim, we used our previously established AD and AI murine PCa cell lines, PLum-AD and PLum-AI, respectively, which recapitulate primary and progressive PCa morphologically and molecularly. We statistically surveyed global gene expressions in these cell lines by microarray analysis. Differential profiles were functionally interrogated by pathways, gene set enrichment and topological gene network analyses.

RESULTS

Gene expression analysis of PLum-AD and PLum-AI transcriptomes (n = 3 each), revealed 723 differentially expressed genes (392 upregulated and 331 downregulated) in PLum-AI compared to PLum-AD cells. Gene set analysis demonstrated enrichment of biological functions and pathways in PLum-AI cells that are central to tumor aggressiveness including cell migration and invasion facilitated by epithelial-to-mesenchymal transition (EMT). Further analysis demonstrated that the p38 mitogen-activated protein kinase (MAPK) was predicted to be significantly activated in the PLum-AI cells, whereas gene sets previously associated with favorable response to the p38 inhibitor SB203580 were attenuated (i.e., inversely enriched) in the PLum-AI cells, suggesting that these aggressive cells may be therapeutically vulnerable to p38 inhibition. Gene set and gene-network analysis also alluded to activation of other signaling networks particularly those associated with enhanced EMT, inflammation and immune function/response including, but not limited to Tnf, IL-6, Mmp 2, Ctgf, and Ptges. Accordingly, we chose SB203580 and IL-6 to validate their effect on PLum-AD and PLum-AI. Some of the common genes identified in the gene-network analysis were validated at the molecular and functional level. Additionally, the vulnerability to SB203580 and the effect of IL-6 were also validated on the stem/progenitor cell population using the sphere formation assay.

CONCLUSIONS

In summary, our study highlights pathways associated with an augmented malignant phenotype in AI cells and presents new high-potential targets to constrain the aggressive malignancy seen in the castration-resistant PCa.

Tracking the expression of therapeutic protein targets in rare cells by antibody-mediated nanoparticle labelling and magnetic sorting

Molecular-level features of tumours can be tracked using single-cell analyses of circulating tumour cells (CTCs). However, single-cell measurements of protein expression for rare CTCs are hampered by the presence of a large number of non-target cells. Here, we show that antibody-mediated labelling of intracellular proteins in the nucleus, mitochondria and cytoplasm of human cells with magnetic nanoparticles enables analysis of target proteins at the single-cell level by sorting the cells according to their nanoparticle content in a microfluidic device with cell-capture zones sandwiched between arrays of magnets. We used the magnetic labelling and cell-sorting approach to track the expression of therapeutic protein targets in CTCs isolated from blood samples of mice with orthotopic prostate xenografts and from patients with metastatic castration-resistant prostate cancer. We also show that mutated proteins that are drug targets or markers of therapeutic response can be directly identified in CTCs, analysed at the single-cell level and used to predict how mice with drug-susceptible and drug-resistant pancreatic tumour xenografts respond to therapy.

The Clinical Application and Potential Roles of Circulating Tumor Cells in Bladder Cancer and Prostate Cancer

Circulating tumor cells (CTCs) are considered to be promising biomarkers in malignant diseases. Recently, molecular profiles of CTCs in prostate cancer (PCa) and the role of CTCs in neoadjuvant chemotherapy and transurethral resections of bladder cancer (BCa) are intensely studied. However, localized PCa and nonmuscle-invasive BCa are less investigated and discussed. Moreover, the benefit and feasibility of clinical applications of CTCs should be critically questioned and reevaluated. This review focuses mainly on clinical issues and lesser on methodologies, and summarizes the quintessence of available works dealing with clinical applications of CTCs in PCa and BCa management.

Oral exposure of sulpiride promotes the proliferation of Brown-Norway rat prostates

The aim of the present study was to establish an animal model of prostatic hyperplasia to explore the mechanisms of this disease. Sulpiride, a specific type 2 dopamine receptor antagonist, causes prostate toxicity by stimulating prolactin (PRL) production. Male Brown-Norway (BN) rats were treated intragastrically (i.g.) with sulpiride (40 and 120 mg/kg daily) and vehicle (i.g., daily) for 4 weeks. The results demonstrated that sulpiride-treatment resulted in increased prostate size, prostate lobe weight, epithelial height and acinar luminal area. Furthermore, prostate lobe weight, epithelial height and acinar luminal area of lateral lobes (LP) significantly increased. These effects were dose dependent. Sulpiride treatment increased serum PRL, follicle-stimulating hormone and testosterone levels, while serum luteinizing hormone levels were reduced. Immunohistochemical analysis revealed that proliferating cell nuclear antigen and B-cell lymphoma-2 were significantly increased in certain sulpiride treated groups. Furthermore, estrogen receptor (ER)-α and androgen receptors were upregulated, while ERβ was downregulated in LP. The expression of stromal cell biomarkers, including vimentin, fibronectin and α-smooth muscle actin were significantly increased in LP following 40 mg/kg sulpiride administration. These results suggest that sulpiride causes LP hyperplasia in BN rats by promoting proliferation and inhibiting prostate cell apoptosis via ERα and AR signaling.

Detection of Circulating Tumor Cells in the Diagnostic Leukapheresis Product of Non-Small-Cell Lung Cancer Patients Comparing CellSearch® and ISET

Circulating tumor cells (CTCs) detected by CellSearch are prognostic in non-small-cell lung cancer (NSCLC), but rarely found. CTCs can be extracted from the blood together with mononuclear cell populations by diagnostic leukapheresis (DLA), therefore concentrating them. However, CellSearch can only process limited DLA volumes (≈2 mL). Therefore, we established a protocol to enumerate CTCs in DLA products with Isolation by SizE of Tumor cells (ISET), and compared CTC counts between CellSearch® and ISET. DLA was performed in NSCLC patients who started a new therapy. With an adapted protocol, ISET could process 10 mL of DLA. CellSearch detected CTCs in a volume equaling 2 × 108 leukocytes (mean 2 mL). CTC counts per mL were compared. Furthermore, the live cell protocol of ISET was tested in eight patients. ISET successfully processed all DLA products-16 with the fixed cell protocol and 8 with the live cell protocol. In total, 10-20 mL of DLA was processed. ISET detected CTCs in 88% (14/16), compared to 69% (11/16, p < 0.05) with CellSearch. ISET also detected higher number of CTCs (ISET median CTC/mL = 4, interquartile range [IQR] = 2-6, CellSearch median CTC/mL = 0.9, IQR = 0-1.8, p < 0.01). Cells positive for the epithelial cell adhesion molecule (EpCAM+) per mL were detected in similar counts by both methods. Eight patients were processed with the live cell protocol. All had EpCAM+, CD45-, CD235- cells isolated by fluorescence-activated cell sorting (FACS). Overall, ISET processed larger volumes and detected higher CTC counts compared to CellSearch. EpCAM+ CTCs were detected in comparable rates.

Identification of core genes associated with prostate cancer progression and outcome via bioinformatics analysis in multiple databases

Abstract

The morbidity and mortality of prostate carcinoma has increased in recent years and has become the second most common ale malignant carcinoma worldwide. The interaction mechanisms between different genes and signaling pathways, however, are still unclear.

Methods

Variation analysis of GSE38241, GSE69223, GSE46602 and GSE104749 were realized by GEO2R in Gene Expression Omnibus database. Function enrichment was analyzed by DAVID.6.8. Furthermore, the PPI network and the significant module were analyzed by Cytoscape, STRING and MCODE.GO. Pathway analysis showed that the 20 candidate genes were closely related to mitosis, cell division, cell cycle phases and the p53 signaling pathway. A total of six independent prognostic factors were identified in GSE21032 and TCGA PRAD. Oncomine database and The Human Protein Atlas were applied to explicit that six core genes were over expression in prostate cancer compared to normal prostate tissue in the process of transcriptional and translational. Finally, gene set enrichment were performed to identified the related pathway of core genes involved in prostate cancer.

Result

Hierarchical clustering analysis revealed that these 20 core genes were mostly related to carcinogenesis and development. CKS2, TK1, MKI67, TOP2A, CCNB1 and RRM2 directly related to the recurrence and prognosis of prostate cancer. This result was verified by TCGA database and GSE21032.

Conclusion

These core genes play a crucial role in tumor carcinogenesis, development, recurrence, metastasis and progression. Identifying these genes could help us to understand the molecular mechanisms and provide potential biomarkers for the diagnosis and treatment of prostate cancer.

Evaluation of PD-L1 expression on circulating tumor cells (CTCs) in patients with advanced urothelial carcinoma (UC)

Immune checkpoint inhibition (ICI) of the PD-1/PD-L1 axis shows durable responses in a subset of patients with metastatic urothelial carcinoma (UC). However, PD-L1 expression in tumor biopsies does not necessarily correlate with response to PD-1/PD-L1 inhibitors. Thus, a reliable predictive biomarker is urgently needed. Here, the expression of PD-L1 on circulating tumor cells (CTCs) in blood from patients with advanced UC was analyzed. For this purpose, an assay to test PD-L1 expression on CTCs using the CellSearch® system was established using cells of five UC cell lines spiked into blood samples from healthy donors and applied to a heterogeneous cohort of UC patients. Enumeration of CTCs was performed in blood samples from 49 patients with advanced UC. PD-L1 expression in ≥1 CTC was found in 10 of 16 CTC-positive samples (63%). Both intra- and inter-patient heterogeneity regarding PD-L1 expression of CTCs were observed. Furthermore, vimentin-expressing CTCs were detected in 4 of 15 CTC-positive samples (27%), independently of PD-L1 analysis. Both CTC detection and presence of CTCs with moderate or strong PD-L1 expression correlated with worse overall survival. Analyses during disease course of three individual patients receiving ICI suggest that apart from CTC numbers also PD-L1 expression on CTCs might potentially indicate disease progression.

This is the first study demonstrating the feasibility to detect CTC-PD-L1 expression in patients with advanced UC using the CellSearch® system. This assay is readily available for clinical application and could be implemented in future clinical trials to evaluate its relevance for predicting and monitoring response to ICI.

Free Fatty Acids Promote the Development of Prostate Cancer by Upregulating Peroxisome Proliferator-Activated Receptor Gamma

Introduction

As one of the most common forms of cancer that threatens men's health, prostate cancer (PCa) is under a trend of increasing morbidity and mortality in most countries. More and more studies have pointed out that obesity is closely linked to the occurrence and development of PCa, although there are still many undiscovered molecular mechanisms between the two.

Methods

In the present study, we compare serum lipid levels in patients with PCa and normal individuals. PCa cells (PC3 and 22RV1) were cultured in vitro, the TC/TG/HDL/GLU assay kit was used to detect the glucose and lipid metabolism level of PCa cells, the flow cytometry technique was used to detect the proliferation ability of PCa cells, and the Transwell was used to detect the invasion and migration ability of PCa cells. Western blot/quantitative real-time PCR was used to detect peroxisome proliferator-activated receptor γ (PPARγ) and vimentin/vascular endothelial growth factor-A (VEGF-A) expression levels, and immunohistochemistry was used to observe tumor-associated gene expression levels in nude mice. All data were analysed using the Independent samples t-test or rank sum test.

Results

We found higher levels of FFA in the serum of patients with PCa. In vitro experiments have demonstrated that high levels of FFA can promote the proliferation, migration and invasion of two PCa cells (PC3 and 22RV1) and affect the energy metabolism of PCa cells. The upregulated PPARγ plays a key role in this process, and vimentin may be involved in this signaling pathway.

Conclusion

We infer that high levels of FFA may promote PCa development by upregulating PPARγ expression.

Dynamic changes of Receptor activator of nuclear factor-κB expression in Circulating Tumor Cells during Denosumab predict treatment effectiveness in Metastatic Breast Cancer

Receptor-activator of nuclear-factor -κB-ligand (RANKL) and its receptor RANK have been recently identified as key players in breast cancer bone metastases. Since Circulating Tumor Cells (CTCs) are considered a crucial step of metastatic process, we explored RANK expression on CTCs in metastatic breast cancer (MBC), and the predictive value of RANK-positive CTCs in monitoring patients during treatment with denosumab (anti-RANKL antibody). To this purpose, we developed a novel CTC assay to quantify RANK-positive CTCs in forty-two bone MBC patients, candidates to denosumab treatment. Companion algorithms ΔAUC and Slope were developed, and correlated with time to first skeletal-related-events (SRE), time to bone metastasis progression and time to visceral metastasis progression. Twenty-seven patients had at least one CTC at baseline and, among these, nineteen (70%) had one or more RANK-positive CTCs. Notably, the baseline total CTCs, but not the RANK-positive, were associated with Time-to-first-SRE, Time-to-Bone-Metastasis-Progression and Time-to-Visceral-Metastasis-Progression. Conversely, during treatment monitoring, positive ΔAUC value, expression of RANK-positive CTCs persistence, correlated with longer Time-to-first-SRE (p = 0.0002) and Time-to-Bone-Metastasis-Progression (p = 0.0012). Furthermore, the early increase at second day, in RANK-positive CTCs (Positive-Slope) was associated with delay in time-to-first-SRE (p = 0.0038) and Time-to-Bone-Metastasis-Progression (p = 0.0024). We demonstrate, for the first time, the expression of RANK on CTCs in MBC patients and that the persistence of RANK expression determines denosumab effectiveness.

Overexpression Of ERβ Participates In The Progression Of Liver Cancer Via Inhibiting The Notch Signaling Pathway

PURPOSE

This study aimed to explore the role of Estrogen Receptor-β (ERβ)-mediated Notch signaling pathway in the regulation of proliferation and apoptosis in liver cancer cells.

METHODS

HepG2 cells (Pbi-EGFP-ER) were transfected with ERβ that mediated by liposome, and normal HepG2 cells (Blank) and empty plasmid-transfected HepG2 cells (Pbi-EGFP-C) were used as controls. Then, Huh7 cells were transfected with shERβ lentivirus to knock down ERβ expression. The Huh7 cells were divided into three groups including Blank, experimental group (shERβ) and negative group (shLuc). Then, qRT-PCR, Western blot, CCK-8 assay, cell scratch assay, Transwell assay, Annexin V-FITC and PI double staining were performed based on these groups. Finally, a mouse xenograft model was constructed to verify the regulation of ERβ on Notch signaling pathway in liver cancer.

RESULTS

In HepG2 cells, the ERβ expression in Pbi-EGFP-E group was higher than that in Blank and Bi-EGFP-C group. Overexpression of ERβ inhibited HepG2 cell proliferation, migration, invasion and Ki67 protein expression, as well as promoted apoptosis, Bcl-2 and Bax expression. Overexpression of ERβ decreased Notch1, Notch2 and Hes1 expression. In Huh7 cells, the effect of low ERβ expression was contrary to that of high ERβ expression. The shERβ + DAPT group reversed the effect of shERβ on the volume and weight of transplanted tumors.

CONCLUSION

ERβ may inhibit the development of liver cancer and promote apoptosis via inhibiting the Notch pathway.

Single-Cell Analysis of Circulating Tumor Cells: How Far Have We Come in the -Omics Era?

Tumor cells detach from the primary tumor or metastatic sites and enter the peripheral blood, often causing metastasis. These cells, named Circulating Tumor Cells (CTCs), display the same spatial and temporal heterogeneity as the primary tumor. Since CTCs are involved in tumor progression, they represent a privileged window to disclose mechanisms of metastases, while -omic analyses at the single-cell level allow dissection of the complex relationships between the tumor subpopulations and the surrounding normal tissue. However, in addition to reporting the proof of concept that we can query CTCs to reveal tumor evolution throughout the continuum of treatment for early detection of resistance to therapy, the scientific literature has also been highlighting the disadvantages of CTCs, which hampers a routine use of this approach in clinical practice. To date, an increasing number of CTC technologies, as well as -omics methods, have been employed, mostly lacking strong comparative analyses. The rarity of CTCs also represents a major challenge, because there is no consensus regarding the minimal criteria necessary and sufficient to define an event as CTC; moreover, we cannot often compare data from of one study with that of another. Finally, the availability of an individual tumor profile undermines the traditional histology-based treatment. Applying molecular data for patient benefit implies a collective effort by biologists, bioengineers, and clinicians, to create tools to interpret molecular data and manage precision medicine in every single patient. Herein, we focus on the most recent findings in CTC −omics to learn how far we have come.

Pathophysiology of Tumor Cell Release into the Circulation and Characterization of CTC

The traditional model of metastatic progression postulates that the ability to form distant metastases is driven by random mutations in cells of the primary tumor.

Liquid Biopsy in Oligometastatic Prostate Cancer-A Biologist's Point of View

Prostate cancer (PCa) is the main cause of cancer-related mortality in males and the diagnosis, treatment, and care of these patients places a great burden on healthcare systems globally. Clinically, PCa is highly heterogeneous, ranging from indolent tumors to highly aggressive disease. In many cases treatment-generally either radiotherapy (RT) or surgery-can be curative. Several key genetic and demographic factors such as age, family history, genetic susceptibility, and race are associated with a high incidence of PCa. While our understanding of PCa, which is mainly based on the tools of molecular biology-has improved dramatically in recent years, efforts to better understand this complex disease have led to the identification of a new type of PCa-oligometastatic PCa. Oligometastatic disease should be considered an individual, heterogeneous entity with distinct metastatic phenotypes and, consequently, wide prognostic variability. In general, patients with oligometastatic disease typically present less biologically aggressive tumors whose metastatic potential is more limited and which are slow-growing. These patients are good candidates for more aggressive treatment approaches. The main aim of the presented review was to evaluate the utility of liquid biopsy for diagnostic purposes in PCa and for use in monitoring disease progression and treatment response, particularly in patients with oligometastatic PCa. Liquid biopsies offer a rapid, non-invasive approach whose use t is expected to play an important role in routine clinical practice to benefit patients. However, more research is needed to resolve the many existing discrepancies with regard to the definition and isolation method for specific biomarkers, as well as the need to determine the most appropriate markers. Consequently, the current priority in this field is to standardize liquid biopsy-based techniques. This review will help to improve understanding of the biology of PCa, particularly the recently defined condition known as "oligometastatic PCa". The presented review of the body of evidence suggests that additional research in molecular biology may help to establish novel treatments for oligometastatic PCa. In the near future, the treatment of PCa will require an interdisciplinary approach involving active cooperation among clinicians, physicians, and biologists.

Research on the establishment of a TPM3 monoclonal stable transfected PANC-1 cell line and the experiment of the EMT occurrence in human pancreatic cancer

Background: Pancreatic cancer is one of the most aggressive human malignancies that is associated with early metastasis and chemoresistance. Tropomyosin (TPM) is an indispensable regulatory protein for muscle contraction, Abnormal expressions of TPM gene are closely related to the carcinogenesis and metastasis of malignant tumors.

Purpose: In this experiment, a monoclonal stable transfected cell line was established by the knock-down of TMP3 expression in PANC-1 cells with the lentivirus method, and the impacts of the downregulated TPM3 gene expression on the EMT-related molecules and biological behaviors of PANC-1 cells were explored.

Methods: Based on the TPM3 gene sequence, we designed the RNA interference sequence, constructed and screened out the recombinant plasmid segment TPM3-shRNA with the optimal silencing effect, and carried out lentivirus titer determination and packaging. The recombinant lentiviral interference vector LV-TPM3-shRNA was transfected into PANC-1 cells; the transfection efficiency was then evaluated to screen out the monoclonal stable transfected PANC-1 cell line with downregulated TPM3 expression. The qRT-PCR and Western blot were used to detect the changes in the gene- and protein-levels expressions of EMT-related transcription factors in the target cell line and to respectively test the variations of the invasion and proliferation capacities.

Results: It is shown that the monoclonal stable transfected PANC-1 cell line with downregulated TPM3 expression was successfully established with the recombinant lentiviral vector. After knocking down the expression of TPM3 gene in PANC-1 cells, EMT occurred in the cells; the cell phenotype showed malignant transformation, and the in vitro biological behaviors of the cells (such as proliferation and invasion) were enhanced to different degrees.

Conclusion: It is indicated that the TPM3 gene can be a potential target spot for the treatment of pancreatic cancer.

Research landscape of liquid biopsies in prostate cancer

Studies show that liquid biopsies are efficient in the detection of circulating cancer products. However, scientific community has not yet implemented this technology in routine clinical practice. Liquid biopsies are less invasive than traditional surgical ones because they rely on the detection of specific biomarkers in readily accessible body fluid samples. The clinical management of prostate cancer depends on the controversial blood serum biomarker PSA (prostate specific antigen). PSA tests have a low accuracy. In addition, a positive PSA result for prostate cancer needs a confirmation through a tissue biopsy. Thus, liquid biopsies are considered tools to find a surrogate biomarker. This review aimed to show the landscape of liquid biopsies in prostate cancer research to understand its challenges and foresee the trends in this area. We performed an exhaustive Pubmed search of articles reporting the study of liquid biopsies in prostate cancer with circulating tumor cells, cell-free nucleic acids and extracellular vesicles as targets. After a thorough analysis, we retrieved sixty-two relevant articles. Among the identified articles, the most used target and body fluid were circulating tumor cells and blood, respectively. Enumeration of circulating tumor cells was the most reported parameter, but it was often combined with other biomarkers. The most used methods for biomarker detection were those based on transcriptome analysis. Despite the vast literature about liquid biopsy in prostate cancer, most studies seem to be stuck on improving the yield of technologies. Consequently, they seem to test a limited number of samples. Larger cohorts could provide robust evidence to translate liquid biopsies of prostate cancer to the clinics.

Predictive Value of Transforming Growth Factor-α and Ki-67 for the Prognosis of Skull Base Chordoma

OBJECTIVE

We aimed to characterize the expression of transforming growth factor-α (TGF-α) and Ki-67 and to assess the relationship between TGF-α and Ki-67 expression and prognostic factors in skull base chordoma.

METHODS

We retrospectively analyzed the data from 46 patients with skull base chordoma. The follow-up duration ranged from 1 to 168 months (mean, 74.1). The survival data were statistically analyzed using the Kaplan-Meier method and multivariate Cox regression analysis. The expression of TGF-α and Ki-67 were detected by immunohistochemical staining of paraffin-embedded patient tissue specimens.

RESULTS

The total resection (TR) group had longer overall survival compared with the non-TR group (P = 0.042). The TR group also had longer progression-free survival (PFS) than did the non-TR group (P = 0.046). The group with a high Ki-67 labeling index (Ki-67LI) had shorter overall survival than did the group with a low Ki-67LI (P = 0.039). Also, the group with a high Ki-67LI had significantly shorter PFS than did the group with a low Ki-67LI (P = 0.016). Moreover, the group with high TGF-α expression had significantly shorter PFS compared with the group with low TGF-α expression (P = 0.005).

CONCLUSIONS

Our results have shown that high levels of TGF-α and Ki-67 are associated with shorter PFS in patients with chordoma. We have confirmed the role of Ki-67 as a functional molecular marker of poor prognosis. We also identified TGF-α as a potential novel biomarker for predicting prognosis for patients with skull base chordoma.

Expression of vimentin in nasopharyngeal carcinoma and its possible molecular mechanism: A study based on immunohistochemistry and bioinformatics analysis

BACKGROUND

Although previous researchers have analyzed the expression level of vimentin in nasopharyngeal carcinoma (NPC), the sample size of each study was too small, and there was no further in-depth study utilizing microarray and RNA-sequencing data. More importantly, the role and molecular mechanism of vimentin in NPC have not yet been addressed comprehensively. Accordingly, the aim of the present research was to conduct a full exploration of the clinical significance of vimentin in NPC in a large sample size.

MATERIALS AND METHODS

Immunohistochemistry was used to test the expression of vimentin in clinical samples. Data from relevant microarray and RNA-sequencing datasets were screened and extracted to explore the clinical role of vimentin in NPC. Subsequently, vimentin-related signaling pathways were investigated via in-silico approaches.

RESULTS

The clinical immunohistochemistry detection showed the positive expression ratio of vimentin was 24.6% (14/57) of the NPC specimens, whereas vimentin expression was negative in nasopharyngitis (NPG) tissues (0/20, P = 0.016). The mRNA and protein levels of vimentin were both remarkably up-regulated in NPC based on 196 and 1566 cases, respectively. The protein level of vimentin was also a risky factor for the prognosis prediction of NPC with the hazard ratios (HR) being 3.831. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses, the localization of vimentin was in both the cytoplasm and the cytoskeleton, and vimentin was involved in the regulation of molecular function, the execution phase of apoptosis, and the regulation of cellular component organization.

CONCLUSION

The high expression of vimentin plays a pivotal role in the development and poor progression of NPC, which indicates that vimentin may be an effective predictive indicator for NPC.

Low-Dose Radiation Enhanced Inhibition of Breast Tumor Xenograft and Reduced Myocardial Injury Induced by Doxorubicin

We reported that low-dose radiation (LDR) alleviated cardiotoxicity of doxorubicin (DOX) via inhibiting myocardial cell apoptosis and oxidative stress in vivo. Here, we tested whether LDR could enhance chemotherapeutic effect of DOX and alleviate myocardial injury induced by DOX by observing cell proliferation, apoptosis, and metastasis of heterotopic tumor in vivo. Mice implanted with 4T1 breast carcinoma cells were given 7.5 mg/kg DOX or 0.9% NaCl solution 72 hours after LDR (0 or 75 mGy). The histology of tumor tissue was observed by hematoxylin and eosin staining, the apoptosis was determined by terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling, and the expression of Ki67, Bcl-2, Bax, cleaved caspase3, matrix metalloproteinase 2 (MMP2), MMP9, and CD34 was detected by Western blot. Expression of Ki67 and CD34 was also detected by immunohistochemistry. Results showed that cell proliferation of the breast tumor and protein expression of the metastasis-related molecules were significantly reduced and the apoptosis of tumor cells was significantly increased in the LDR + DOX-treated tumor-bearing mice. Pretreatment with LDR significantly prevented DOX-induced cardiotoxicity likely through preventing DOX-induced mitochondrial Bcl2/Bax dyshomeostasis-induced caspase-3 cleavage-dependent apoptosis. These results suggested that LDR not only enhances DOX antitumor effect but also reduces DOX cardiotoxicity, which may potentially overcome the limitation for DOX clinical usage.

Ki-67 is an independent prognostic marker for the recurrence and relapse of oral squamous cell carcinoma

As a nuclear and nucleolar protein, proliferation marker protein Ki-67 (Ki-67) serves a vital role in tumorigenesis due to its positive correlation with tumor proliferation. High expression of Ki-67 in the cell cycle from the G₁ to M phase makes it a potential biomarker for certain tumors and useful for selecting medical treatment. However, the diagnostic value of Ki-67 in oral squamous cell carcinoma (OSCC) has not been fully evaluated. In the present study, the objective was the elucidation of the prognostic value of Ki-67 in a large number of OSCC patients. Ki-67 expression was detected by immunohistochemical staining methods in 298 OSCC specimens and 98 tumor-free oral mucosa specimens (62 dysplasia mucosa and 36 normal mucosa), acquired from Nanjing Stomatological Hospital, Medical School of Nanjing University (Nanjing, China). Expression of Ki-67 in normal tissues, dysplasia tissues and OSCC tissues was compared. Associations between Ki-67 expression and clinicopathological parameters were analyzed by χ² test. Kaplan-Meier survival curves and Cox progression analysis were used to assess the diagnostic value of Ki-67 for OSCC. The results showed that Ki-67 expression was higher in OSCC tissues than in tumor-free tissues and that it increased with the progression of dysplasia in oral mucosa tissues. In addition, patients with high Ki-67 expression had a worse clinical outcome, including poor tumor differentiation (P=0.001), increased positive lymph node metastasis (P=0.006) and increased worst pattern of invasion type (P<0.0001). Kaplan-Meier survival analysis demonstrated that higher Ki-67 expression was associated with poorer overall survival (OS) (P=0.035), recurrence-free survival (RFS) (P=0.017), metastasis-free survival (MFS) (P=0.032) and disease-free survival (DFS) (P=0.018) times. Additional multivariate analysis demonstrated that Ki-67 expression was negatively associated with OS, DFS, RFS and MFS. In conclusion, Ki-67 overexpression is associated with the progression of OSCC and serves as an independent prognostic factor for OSCC patients.

An Optically Induced Dielectrophoresis (ODEP)-Based Microfluidic System for the Isolation of High-Purity CD45neg/EpCAMneg Cells from the Blood Samples of Cancer Patients-Demonstration and Initial Exploration of the Clinical Significance of These Cells

Circulating tumour cells (CTCs) in blood circulation play an important role in cancer metastasis. CTCs are generally defined as the cells in circulating blood expressing the surface antigen EpCAM (epithelial cell adhesion molecule). Nevertheless, CTCs with a highly metastatic nature might undergo an epithelial-to-mesenchymal transition (EMT), after which their EpCAM expression is downregulated. In current CTC-related studies, however, these clinically important CTCs with high relevance to cancer metastasis could be missed due to the use of the conventional CTC isolation methodologies. To precisely explore the clinical significance of these cells (i.e., CD45^neg/EpCAM^neg cells), the high-purity isolation of these cells from blood samples is required. To achieve this isolation, the integration of fluorescence microscopic imaging and optically induced dielectrophoresis (ODEP)-based cell manipulation in a microfluidic system was proposed. In this study, an ODEP microfluidic system was developed. The optimal ODEP operating conditions and the performance of live CD45^neg/EpCAM^neg cell isolation were evaluated. The results demonstrated that the proposed system was capable of isolating live CD45^neg/EpCAM^neg cells with a purity as high as 100%, which is greater than the purity attainable using the existing techniques for similar tasks. As a demonstration case, the cancer-related gene expression of CD45^neg/EpCAM^neg cells isolated from the blood samples of healthy donors and cancer patients was successfully compared. The initial results indicate that the CD45^neg/EpCAM^neg nucleated cell population in the blood samples of cancer patients might contain cancer-related cells, particularly EMT-transformed CTCs, as suggested by the high detection rate of vimentin gene expression. Overall, this study presents an ODEP microfluidic system capable of simply and effectively isolating a specific, rare cell species from a cell mixture.

Concise Review: Prostate Cancer Stem Cells: Current Understanding

Prostate cancer (PCa) is heterogeneous, harboring phenotypically diverse cancer cell types. PCa cell heterogeneity is caused by genomic instability that leads to the clonal competition and evolution of the cancer genome and by epigenetic mechanisms that result in subclonal cellular differentiation. The process of tumor cell differentiation is initiated from a population of prostate cancer stem cells (PCSCs) that possess many phenotypic and functional properties of normal stem cells. Since the initial reports on PCSCs in 2005, there has been much effort to elucidate their biological properties, including unique metabolic characteristics. In this Review, we discuss the current methods for PCSC enrichment and analysis, the hallmarks of PCSC metabolism, and the role of PCSCs in tumor progression. Stem Cells 2018;36:1457-1474.

EMT circulating tumor cells detected by cell-surface vimentin are associated with prostate cancer progression

Recent advances in the field of circulating tumor cells (CTC) have shown promise in this liquid biopsy-based prognosis of patient outcome. However, not all of the circulating cells are tumor cells, as evidenced by a lack of tumor-specific markers. The current FDA standard for capturing CTCs (CellSearch) relies on an epithelial marker and cells captured via CellSearch cannot be considered to have undergone EMT. Therefore, it is difficult to ascertain the presence and relevance of any mesenchymal or EMT-like CTCs. To address this gap in technology, we recently discovered the utility of cell-surface vimentin (CSV) as a marker for detecting mesenchymal CTCs from sarcoma, breast, and colon cancer. Here we studied peripheral blood samples of 48 prostate cancer (PCA) patients including hormone sensitive and castration resistant sub-groups. Blood samples were analyzed for three different properties including our own CSV-based CTC enumeration (using 84-1 mAb against CSV), CellSearch-based epithelial CTC counts, and serum prostate-specific antigen (PSA) quantification. Our data demonstrated that in comparison with CellSearch, the CSV-based method had greater sensitivity and specificity. Further, we observed significantly greater numbers of CTCs in castration resistant patients as measured by our CSV method but not CellSearch. Our data suggests CSV-guided CTC enumeration may hold prognostic value and should be further validated as a possible measurement of PCA progression towards the deadly, androgen-independent form.

Expanded Genomic Profiling of Circulating Tumor Cells in Metastatic Breast Cancer Patients to Assess Biomarker Status and Biology Over Time (CALGB 40502 and CALGB 40503, Alliance)

Purpose: We profiled circulating tumor cells (CTCs) to study the biology of blood-borne metastasis and to monitor biomarker status in metastatic breast cancer (MBC).Methods: CTCs were isolated from 105 patients with MBC using EPCAM-based immunomagnetic enrichment and fluorescence-activated cells sorting (IE/FACS), 28 of whom had serial CTC analysis (74 samples, 2-5 time points). CTCs were subjected to microfluidic-based multiplex QPCR array of 64 cancer-related genes (n = 151) and genome-wide copy-number analysis by array comparative genomic hybridization (aCGH; n = 49).Results: Combined transcriptional and genomic profiling showed that CTCs were 26% ESR1-ERBB2-, 48% ESR1+ERBB2-, and 27% ERBB2+ Serial testing showed that ERBB2 status was more stable over time compared with ESR1 and proliferation (MKI67) status. While cell-to-cell heterogeneity was observed at the single-cell level, with increasingly stable expression in larger pools, patient-specific CTC expression "fingerprints" were also observed. CTC copy-number profiles clustered into three groups based on the extent of genomic aberrations and the presence of large chromosomal imbalances. Comparative analysis showed discordance in ESR1/ER (27%) and ERBB2/HER2 (23%) status between CTCs and matched primary tumors. CTCs in 65% of the patients were considered to have low proliferation potential. Patients who harbored CTCs with high proliferation (MKI67) status had significantly reduced progression-free survival (P = 0.0011) and overall survival (P = 0.0095) compared with patients with low proliferative CTCs.Conclusions: We demonstrate an approach for complete isolation of EPCAM-positive CTCs and downstream comprehensive transcriptional/genomic characterization to examine the biology and assess breast cancer biomarkers in these cells over time. Clin Cancer Res; 24(6); 1486-99. ©2018 AACR.

Circulating and disseminated tumor cells: diagnostic tools and therapeutic targets in motion

Enumeration of circulating tumor cells (CTCs) in peripheral blood with the gold standard CellSearchTM has proven prognostic value for tumor recurrence and progression of metastatic disease. Therefore, the further molecular characterization of isolated CTCs might have clinical relevance as liquid biopsy for therapeutic decision-making and to monitor disease progression. The direct analysis of systemic cancer appears particularly important in view of the known disparity in expression of therapeutic targets as well as epithelial-to-mesenchymal transition (EMT)-based heterogeneity between primary and systemic tumor cells, which all substantially complicate monitoring and therapeutic targeting at present. Since CTCs are the potential precursor cells of metastasis, their in-depth molecular profiling should also provide a useful resource for target discovery. The present review will discuss the use of systemically spread cancer cells as liquid biopsy and focus on potential target antigens.

Epithelial-to-mesenchymal transition leads to disease-stage differences in circulating tumor cell detection and metastasis in pre-clinical models of prostate cancer

Metastasis is the cause of most prostate cancer (PCa) deaths and has been associated with circulating tumor cells (CTCs). The presence of ≥5 CTCs/7.5mL of blood is a poor prognosis indicator in metastatic PCa when assessed by the CellSearch^® system, the “gold standard” clinical platform. However, ~35% of metastatic PCa patients assessed by CellSearch^® have undetectable CTCs. We hypothesize that this is due to epithelial-to-mesenchymal transition (EMT) and subsequent loss of necessary CTC detection markers, with important implications for PCa metastasis. Two pre-clinical assays were developed to assess human CTCs in xenograft models; one comparable to CellSearch^® (EpCAM-based) and one detecting CTCs semi-independent of EMT status via combined staining with EpCAM/HLA (human leukocyte antigen). In vivo differences in CTC generation, kinetics, metastasis and EMT status were determined using 4 PCa models with progressive epithelial (LNCaP, LNCaP-C42B) to mesenchymal (PC-3, PC-3M) phenotypes. Assay validation demonstrated that the CellSearch^®-based assay failed to detect a significant number (~40-50%) of mesenchymal CTCs. In vivo, PCa with an increasingly mesenchymal phenotype shed greater numbers of CTCs more quickly and with greater metastatic capacity than PCa with an epithelial phenotype. Notably, the CellSearch^®-based assay captured the majority of CTCs shed during early-stage disease in vivo, and only after establishment of metastases were a significant number of undetectable CTCs present. This study provides important insight into the influence of EMT on CTC generation and subsequent metastasis, and highlights that novel technologies aimed at capturing mesenchymal CTCs may only be useful in the setting of advanced metastatic disease.

Molecular analysis of circulating tumors cells: Biomarkers beyond enumeration

Advances in our molecular understanding of cancer biology have paved the way to an expanding compendium of molecularly-targeted therapies, accompanied by the urgent need for biomarkers that enable the precise selection of the most appropriate therapies for individual cancer patients. Circulating biomarkers such as circulating tumor cells (CTCs) are poised to fill this need, since they are "liquid biopsies" that can be performed non-invasively and serially, and may capture the spectrum of spatial and temporal tumor heterogeneity better than conventional tissue biopsies. Increasing evidence suggests that moving beyond the enumeration of CTCs towards more sophisticated molecular analyses can provide actionable data that may predict and potentially improve clinical outcomes. In this review, we discuss the potential of molecular CTC analyses to serve as prognostic and predictive biomarkers to guide cancer therapy and early cancer detection. As technologies to capture and analyze CTCs continue to increase in sophistication, we anticipate that the potential clinical applications of CTCs will grow exponentially in the coming years.

Clinical applications of the CellSearch platform in cancer patients

The CellSearch® system (CS) enables standardized enrichment and enumeration of circulating tumor cells (CTCs) that are repeatedly assessable via non-invasive "liquid biopsy". While the association of CTCs with poor clinical outcome for cancer patients has clearly been demonstrated in numerous clinical studies, utilizing CTCs for the identification of therapeutic targets, stratification of patients for targeted therapies and uncovering mechanisms of resistance is still under investigation. Here, we comprehensively review the current benefits and drawbacks of clinical CTC analyses for patients with metastatic and non-metastatic tumors. Furthermore, the review focuses on approaches beyond CTC enumeration that aim to uncover therapeutically relevant antigens, genomic aberrations, transcriptional profiles and epigenetic alterations of CTCs at a single cell level. This characterization of CTCs may shed light on the heterogeneity and genomic landscapes of malignant tumors, an understanding of which is highly important for the development of new therapeutic strategies.

Circulating Tumor Cells and Implications of the Epithelial-to-Mesenchymal Transition

The majority of cancer-related deaths result from metastasis, the process by which cancer cells escape the primary tumor site and enter into the blood circulation in order to disseminate to secondary locations throughout the body. Tumor cells found within the circulation are referred to as circulating tumor cells (CTCs), and their detection and enumeration correlate with poor prognosis. The epithelial-to-mesenchymal transition (EMT) is a dynamic process that imparts epithelial cells with mesenchymal-like properties, thus facilitating tumor cell dissemination and contributing to metastasis. However, EMT also results in the downregulation of various epithelial proteins typically utilized by CTC technologies for enrichment and detection of these rare cells, resulting in reduced detection of some CTCs, potentially those with a more metastatic phenotype. In addition to the current clinical role of CTCs as a prognostic biomarker, they also have potential as a predictive biomarker via CTC characterization. However, CTC characterization is complicated by the unknown biological significance of CTCs possessing an EMT-like phenotype, and the ability to capture and understand this CTC subpopulation is an essential step in the utilization of CTCs for patient management. This chapter will review the process of EMT and its contribution to metastasis; discusses current and future clinical applications of CTCs; and describes both traditional and novel methods for CTC enrichment, detection, and characterization with a specific focus on CTCs with an EMT phenotype.

The effect of aspirin on circulating tumor cells in metastatic colorectal and breast cancer patients: a phase II trial study

PURPOSE

Aspirin could reduce the risk of cancer metastasis. Circulating tumor cells (CTCs) are a key factor of cancer metastasis, but no evidence has revealed how aspirin affects CTCs and its epithelial-mesenchymal transition (EMT). Here, we conducted a clinical trial to investigate how aspirin affects CTCs in metastatic colorectal cancer (MCC) and breast cancer patients (MBC).

METHODS

The trial is retrospective registered at clinicaltrials.gov (NCT02602938). The eligible patients are given 100 mg aspirin q.d. for 8 weeks, and CTCs are evaluated at baseline, 4 and 8 weeks for absolute number, phenotype (epithelial type, E+, mesenchymal type, M+, and biophenotypic type, B+), and vimentin expression.

RESULTS

Data on 21 MCC and 19 MBC patients are analyzed, and it revealed that the CTC numbers decreased with aspirin treatment in MCC (p < 0.001) but not MBC (p = 0.0532); besides, ratio of E+ CTCs increased (p = 0.037) and M+ CTCs decreased at 2 months in MCC (p = 0.013), but neither the ratio of E+ or M+ CTCs changes significantly in MBC; vimentin expression of M+ CTCs is higher than E+ and B+ CTCs either in MBC or MCC patients at baseline (p < 0.01); and aspirin suppresses the vimentin expression in M+ (p = 0.002)and B+ (p = 0.006) CTCs of MCC and M+ CTCs of MBC (p = 0.004); besides it find vimentin expression in B+ (p = 0.004) or M+ (p < 0.001), CTCs are markedly decreased in patients with total CTC numbers declined.

CONCLUSION

Aspirin could decrease CTCs numbers and block EMT transition in MCC patients and part of MBC patients.