Cell-surface vimentin-positive macrophage-like circulating tumor cells as a novel biomarker of metastatic gastrointestinal stromal tumors

Exploring new frontiers: cell surface vimentin as an emerging marker for circulating tumor cells and a promising therapeutic target in advanced gastric Cancer

BACKGROUND

Circulating tumor cells (CTCs) hold immense promise in guiding treatment strategies for advanced gastric cancer (GC). However, their clinical impact has been limited due to challenges in identifying epithelial-mesenchymal transition (EMT)-CTCs using conventional methods.

METHODS

To bridge this knowledge gap, we established a detection platform for CTCs based on the distinctive biomarker cell surface vimentin (CSV). A prospective study involving 127 GC patients was conducted, comparing CTCs enumeration using both EpCAM and CSV. This approach enabled the detection of both regular and EMT-CTCs, providing a comprehensive analysis. Spiking assays and WES were employed to verify the reliability of this marker and technique. To explore the potential inducer of CSV+CTCs formation, a combination of Tandem Mass Tag (TMT) quantitative proteomics, m6A RNA immunoprecipitation-qPCR (MeRIP-qPCR), single-base elongation- and ligation-based qPCR amplification method (SELECT) and RNA sequencing (RNA-seq) were utilized to screen and confirm the potential target gene. Both in vitro and in vivo experiments were performed to explore the molecular mechanism of CSV expression regulation and its role in GC metastasis.

RESULTS

Our findings revealed the potential of CSV in predicting therapeutic responses and long-term prognosis for advanced GC patients. Additionally, compared to the conventional EpCAM-based CTCs detection method, the CSV-specific positive selection CTCs assay was significantly better for evaluating the therapeutic response and prognosis in advanced GC patients and successfully predicted disease progression 14.25 months earlier than radiology evaluation. Apart from its excellent role as a detection marker, CSV emerges as a promising therapeutic target for attenuating GC metastasis. It was found that fat mass and obesity associated protein (FTO) could act as a potential catalyst for CSV+CTCs formation, and its impact on the insulin-like growth factor-I receptor (IGF-IR) mRNA decay through m6A modification. The activation of IGF-I/IGF-IR signaling enhanced the translocation of vimentin from the cytoplasm to the cell surface through phosphorylation of vimentin at serine 39 (S39). In a GC mouse model, the simultaneous inhibition of CSV and blockade of the IGF-IR pathway yielded promising outcomes.

CONCLUSION

In summary, leveraging CSV as a universal CTCs marker represents a significant breakthrough in advancing personalized medicine for patients with advanced GC. This research not only paves the way for tailored therapeutic strategies but also underscores the pivotal role of CSV in enhancing GC management, opening new frontiers for precision medicine.

The Hallmarks of Circulating Hybrid Cells

While tumor metastases represent the primary driver of cancer-related mortality, our understanding of the mechanisms that underlie metastatic initiation and progression remains incomplete. Recent work identified a novel tumor-macrophage hybrid cell population, generated through the fusion between neoplastic and immune cells. These hybrid cells are detected in primary tumor tissue, peripheral blood, and in metastatic sites. In-depth analyses of hybrid cell biology indicate that they can exploit phenotypic properties of both parental tumor and immune cells, in order to intravasate into circulation, evade the immune response, and seed tumors at distant sites. Thus, it has become increasingly evident that the development and dissemination of tumor-immune hybrid cells play an intricate and fundamental role in the metastatic cascade and can provide invaluable information regarding tumor characteristics and patient prognostication. In this chapter, we review the current understanding of this novel hybrid cell population, the specific hallmarks of cancer that these cells exploit to promote cancer progression and metastasis, and discuss exciting new frontiers that remain to be explored.

Linker optimization and activity validation of a cell surface vimentin targeted homo-dimeric peptoid antagonist for lung cancer stem cells

Epithelial-to-mesenchymal transition (EMT) endows epithelia-derived cancer cells with properties of stem cells that govern cancer invasion and metastasis. Vimentin is one of the best studied EMT markers and recent reports indicate that vimentin interestingly translocated onto cell surface under various tumor conditions. We recently reported a cell surface vimentin (CSV) specific peptoid antagonist named JM3A. We now investigated the selective antagonist activity of the optimized homo-dimeric version of JM3A, JM3A-L2D on stem-like cancer cells or cancer stem cells (CSCs) over normal cells in non-small cell lung cancer (NSCLC). Homo-dimerization of JM3A provided the avidity effect and improved the biological activity compared to the monomeric version. We first optimized the central linker length of the dimer by designing seven JM3A derivatives with varying linker lengths/types and evaluated the anti-cancer activity using the standard MTS cell viability assay. The most optimized derivative contains a central lysine linker and two glycines, named JM3A-L2D, which displayed 100 nM vimentin binding affinity (Kd) with an anti-cancer activity (IC50) of 6.7 µM on H1299 NSCLC cells. This is a 190-fold improvement in binding over the original JM3A. JM3A-L2D exhibited better potency on high vimentin-expressing NSCLC cells (H1299 and H460) compared to low vimentin-expressing NSCLC cells (H2122). No activity was observed on normal bronchial HBEC3-KT cells. The anti-CSC activity of JM3A-L2D was evaluated using the standard colony formation assay and JM3A-L2D disrupted the colony formation with IC50 ∼ 400 nM. In addition, JM3A-L2D inhibited cell migration activity at IC50 ∼ 2 µM, assessed via wound healing assay. The underlying mechanism of action seems to be the induction of apoptosis by JM3A-L2D on high-vimentin expressing H1229 and H460 NSCLC cells. Our optimized highly CSV selective peptoid has the potential to be developed as an anti-cancer drug candidate, especially considering the high serum stability and economical synthesis of peptoids.

Vimentin takes a hike - Emerging roles of extracellular vimentin in cancer and wound healing

Vimentin is a cytoskeletal protein important for many cellular processes, including proliferation, migration, invasion, stress resistance, signaling, and many more. The vimentin-deficient mouse has revealed many of these functions as it has numerous severe phenotypes, many of which are found only following a suitable challenge or stress. While these functions are usually related to vimentin as a major intracellular protein, vimentin is also emerging as an extracellular protein, exposed at the cell surface in an oligomeric form or secreted to the extracellular environment in soluble and vesicle-bound forms. Thus, this review explores the roles of the extracellular pool of vimentin (eVIM), identified in both normal and pathological states. It focuses specifically on the recent advances regarding the role of eVIM in wound healing and cancer. Finally, it discusses new technologies and future perspectives for the clinical application of eVIM.

Advances in immunology and immunotherapy for mesenchymal gastrointestinal cancers

Mesenchymal gastrointestinal cancers are represented by the gastrointestinal stromal tumors (GISTs) which occur throughout the whole gastrointestinal tract, and affect human health and economy globally. Curative surgical resections and tyrosine kinase inhibitors (TKIs) are the main managements for localized GISTs and recurrent/metastatic GISTs, respectively. Despite multi-lines of TKIs treatments prolonged the survival time of recurrent/metastatic GISTs by delaying the relapse and metastasis of the tumor, drug resistance developed quickly and inevitably, and became the huge obstacle for stopping disease progression. Immunotherapy, which is typically represented by immune checkpoint inhibitors (ICIs), has achieved great success in several solid tumors by reactivating the host immune system, and been proposed as an alternative choice for GIST treatment. Substantial efforts have been devoted to the research of immunology and immunotherapy for GIST, and great achievements have been made. Generally, the intratumoral immune cell level and the immune-related gene expressions are influenced by metastasis status, anatomical locations, driver gene mutations of the tumor, and modulated by imatinib therapy. Systemic inflammatory biomarkers are regarded as prognostic indicators of GIST and closely associated with its clinicopathological features. The efficacy of immunotherapy strategies for GIST has been widely explored in pre-clinical cell and mouse models and clinical experiments in human, and some patients did benefit from ICIs. This review comprehensively summarizes the up-to-date advancements of immunology, immunotherapy and research models for GIST, and provides new insights and perspectives for future studies.

Cell Surface Vimentin Detection in Cancer Cells by Peptide-Based Monoclonal Antibody

Background

Vimentin is a prominent Intermediate Filaments (IFs) protein expressed in different mesenchymal origin cell types. Besides a wide range of cellular function roles associated with vimentin expression, its dysregulation and cell surface expression in the induction of malignancy properties have been reported extensively, making it a promising cancer-specific target. Therefore, this study aimed to generate and characterize anti-vimentin monoclonal antibodies.

Methods

A 14-mer synthetic peptide from vimentin was conjugated to Keyhole Limpet Hemocyanin (KLH) and used for immunization of Blab/C mice and monoclonal production by conventional hybridoma technology. The monoclonal antibody was purified using affinity chromatography of supernatants from the selected hybridoma cells. ELISA, Immunoprecipitation-Western blotting (IP-WB), Immunocytochemistry (ICC), and flow cytometry were employed to characterize the produced monoclonal antibody in terms of interaction with vimentin immunizing peptide as well as vimentin protein.

Results

Amid the several obtained producing anti-vimentin antibody hybridomas, the 7C11-D9 clone (IgG1 isotype with kappa light chain) showed higher reactivity with the immunizing peptide, and led to its selection for purification and characterization. The purified antibody could detect vimentin protein in IP-WB, ICC and flow cytometry of the normal and cancerous cells with different origin. No vimentin expression was found in normal healthy Peripheral Blood Mononuclear Cell (PBMC).

Conclusion

Taken together, 7C11-D9 anti-vimentin monoclonal antibody might be used as immune diagnostic or immune therapeutic tool where detection or targeting of vimentin in a wide range of organisms is required.

The mesenchymal circulating tumor cells as biomarker for prognosis prediction and supervision in hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is one of the most common cancers and a leading cause of death worldwide. Accurate prognosis prediction tools are urgently needed. While the use of circulating tumor cells (CTCs) as prognostic prediction tool has a clear potential.

METHODS

We established a comprehensive, negative enrichment-based strategy for CTCs analysis in patients with HCC, involving identification of epithelial CTCs (E-CTCs) and mesenchymal CTCs (M-CTCs) through specific biomarker. This strategy was performed in 127 HCC cases, 21 nonmalignant liver disease (NMLD) patients and 42 health control to analyze the relevance between CTCs and tumor recurrence.

RESULTS

The total CTC number and M-CTC percent were positively correlated with tumor malignancy and high recurrence risk. Individually, preoperative total CTC number and M-CTC percent could robustly distinguish relapse cases from those with no relapse, with sensitivity of 80.95% and 90.48%, specificity of 74.12% and 84.71%, respectively. Levels of preoperative total CTC number and M-CTC percent can both be regarded as independent risk factors for HCC with early recurrence (P = 0.0053, P < 0.0001), and are both significantly correlated with worse recurrence-free survival (RFS) (log rank P < 0.0001; HR 7.78, 95% CI = 3.59-16.87; log rank P < 0.0001; HR 24.4, 95% CI = 8.67-68.77). The levels of total CTC number and M-CTC number had higher effectiveness than alpha fetal protein (AFP) in HCC longitudinal supervision (77.78% vs 88.89% vs 22.22%).

CONCLUSION

Preoperative and postoperative CTCs with higher effectiveness than AFP in prognosis prediction and recurrence supervision, indicating that CTCs could work as the biomarker for HCC clinical management.

Membrane-Anchored and Tumor-Targeted IL12 (attIL12)-PBMC Therapy for Osteosarcoma

PURPOSE

Chimeric antigen receptor (CAR) T-cell therapy has shown great promise for treating hematologic malignancies but requires a long duration of T-cell expansion, is associated with severe toxicity, and has limited efficacy for treating solid tumors. We designed experiments to address those challenges.

EXPERIMENTAL DESIGN

We generated a cell membrane-anchored and tumor-targeted IL12 (attIL12) to arm peripheral blood mononuclear cells (PBMC) instead of T cells to omit the expansion phase for required CAR T cells.

RESULTS

This IL12-based attIL12-PBMC therapy showed significant antitumor efficacy in both heterogeneous osteosarcoma patient-derived xenograft tumors and metastatic osteosarcoma tumors with no observable toxic effects. Mechanistically, attIL12-PBMC treatment resulted in tumor-restricted antitumor cytokine release and accumulation of attIL12-PBMCs in tumors. It also induced terminal differentiation of osteosarcoma cells into bone-like cells to impede tumor growth.

CONCLUSIONS

In summary, attIL12-PBMC therapy is safe and effective against osteosarcoma. Our goal is to move this treatment into a clinical trial. Owing to the convenience of the attIL12-PBMC production process, we believe it will be feasible.

Circulating Cells with Macrophage-like Characteristics in Cancer: The Importance of Circulating Neoplastic-Immune Hybrid Cells in Cancer

Simple Summary

In cancer, disseminated neoplastic cells circulating in blood are a source of tumor DNA, RNA, and protein, which can be harnessed to diagnose, monitor, and better understand the biology of the tumor from which they are derived. Historically, circulating tumor cells (CTCs) have dominated this field of study. While CTCs are shed directly into circulation from a primary tumor, they remain relatively rare, particularly in early stages of disease, and thus are difficult to utilize as a reliable cancer biomarker. Neoplastic-immune hybrid cells represent a novel subpopulation of circulating cells that are more reliably attainable as compared to their CTC counterparts. Here, we review two recently identified circulating cell populations in cancer—cancer-associated macrophage-like cells and circulating hybrid cells—and discuss the future impact for the exciting area of disseminated hybrid cells.

Abstract

Cancer remains a significant cause of mortality in developed countries, due in part to difficulties in early detection, understanding disease biology, and assessing treatment response. If effectively harnessed, circulating biomarkers promise to fulfill these needs through non-invasive “liquid” biopsy. While tumors disseminate genetic material and cellular debris into circulation, identifying clinically relevant information from these analytes has proven difficult. In contrast, cell-based circulating biomarkers have multiple advantages, including a source for tumor DNA and protein, and as a cellular reflection of the evolving tumor. While circulating tumor cells (CTCs) have dominated the circulating cell biomarker field, their clinical utility beyond that of prognostication has remained elusive, due to their rarity. Recently, two novel populations of circulating tumor-immune hybrid cells in cancer have been characterized: cancer-associated macrophage-like cells (CAMLs) and circulating hybrid cells (CHCs). CAMLs are macrophage-like cells containing phagocytosed tumor material, while CHCs can result from cell fusion between cancer and immune cells and play a role in the metastatic cascade. Both are detected in higher numbers than CTCs in peripheral blood and demonstrate utility in prognostication and assessing treatment response. Additionally, both cell populations are heterogeneous in their genetic, transcriptomic, and proteomic signatures, and thus have the potential to inform on heterogeneity within tumors. Herein, we review the advances in this exciting field.

Prognostic Value of Cell-Surface Vimentin-Positive CTCs in Pediatric Sarcomas

BACKGROUND

Despite advances in care, the 5 year overall survival for patients with relapsed and or metastatic sarcoma remains as low as < 35%. Currently, there are no biomarkers available to assess disease status in patients with sarcomas and as such, disease surveillance remains reliant on serial imaging which increases the risk of secondary malignancies and heightens patient anxiety.

METHODS

Here, for the first time reported in the literature, we have enumerated the cell surface vimentin (CSV+) CTCs in the blood of 92 sarcoma pediatric and adolescent and young adult (AYA) patients as a possible marker of disease.

RESULTS

We constructed a ROC with an AUC of 0.831 resulting in a sensitivity of 85.3% and a specificity of 75%. Additionally, patients who were deemed to be CSV+ CTC positive were found to have a worse overall survival compared to those who were CSV+ CTC negative. We additionally found the use of available molecular testing increased the accuracy of our diagnostic and prognostic tests.

CONCLUSIONS

Our findings indicate that CSV+ CTCs have prognostic value and can possibly serve as a measure of disease burden.

Heterogeneous Circulating Tumor Cells in Sarcoma: Implication for Clinical Practice

Simple Summary

The present review is aimed to discuss the relevance of assaying for the presence and isolation of circulating tumor cells (CTCs) in patients with sarcoma. Just a few studies have been performed to detect and enumerate viable CTCs in sarcoma and a majority of them still represent proof-of-concept studies, while more frequently tumor cells have been detected in the circulation by using the PCR-based method. Nevertheless, recent advances in technologies allowed detection of epithelial–mesenchymal transitioned CTCs from patients with mesenchymal malignancies, despite results being mostly preliminary. The possibility to identify CTCs holds a great promise for both applications of liquid biopsy in sarcoma for precision medicine, and for research purposes to pinpoint the mechanism of the metastatic process through the characterization of tumor mesenchymal cells. Coherently, clinical trials in sarcoma have been designed accordingly to detect CTCs, for diagnosis, identification of novel therapeutic targets and resistance mechanisms of systemic therapies, and patient stratification.

Abstract

Bone and soft tissue sarcomas (STSs) represent a group of heterogeneous rare malignant tumors of mesenchymal origin, with a poor prognosis. Due to their low incidence, only a few studies have been reported addressing circulating tumor cells (CTCs) in sarcoma, despite the well-documented relevance for applications of liquid biopsy in precision medicine. In the present review, the most recent data relative to the detection and isolation of viable and intact CTCs in these tumors will be reviewed, and the heterogeneity in CTCs will be discussed. The relevance of epithelial–mesenchymal plasticity and stemness in defining the phenotypic and functional properties of these rare cells in sarcoma will be highlighted. Of note, the existence of dynamic epithelial–mesenchymal transition (EMT)-related processes in sarcoma tumors has only recently been related to their clinical aggressiveness. Also, the presence of epithelial cell adhesion molecule (EpCAM)-positive CTC in sarcoma has been weakly correlated with poor outcome and disease progression, thus proving the existence of both epithelial and mesenchymal CTC in sarcoma. The advancement in technologies for capturing and enumerating all diverse CTCs phenotype originating from these mesenchymal tumors are presented, and results provide a promising basis for clinical application of CTC detection in sarcoma.

Point-of-care cancer diagnostic devices: From academic research to clinical translation

Early and timely diagnosis of cancer plays a decisive role in appropriate treatment and improves clinical outcomes, improving public health. Significant advances in biosensor technologies are leading to the development of point-of-care (POC) diagnostics, making the testing process faster, easier, cost-effective, and suitable for on-site measurements. Moreover, the incorporation of various nanomaterials into the sensing platforms has yielded POC testing (POCT) platforms with enhanced sensitivity, cost-effectiveness and simplified detection schemes. POC cancer diagnostic devices provide promising platforms for cancer biomarker detection as compared to conventional in vitro diagnostics, which are time-consuming and require sophisticated instrumentation, centralized laboratories, and experienced operators. Current innovative approaches in POC technologies, including biosensors, smartphone interfaces, and lab-on-a-chip (LOC) devices are expected to quickly transform the healthcare landscape. However, only a few cancer POC devices (e.g. lateral flow platforms) have been translated from research laboratories to clinical care, likely due to challenges include sampling procedures, low levels of sensitivity and specificity in clinical samples, system integration and signal readout requirements. In this review, we emphasize recent advances in POC diagnostic devices for cancer biomarker detection and discuss the critical challenges which must be surmounted to facilitate their translation into clinical settings.

Sarcoma treatment in the era of molecular medicine

Sarcomas are heterogeneous and clinically challenging soft tissue and bone cancers. Although constituting only 1% of all human malignancies, sarcomas represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. More than 100 histological subtypes have been characterized to date, and many more are being discovered due to molecular profiling. Owing to their mostly aggressive biological behavior, relative rarity, and occurrence at virtually every anatomical site, many sarcoma subtypes are in particular difficult-to-treat categories. Current multimodal treatment concepts combine surgery, polychemotherapy (with/without local hyperthermia), irradiation, immunotherapy, and/or targeted therapeutics. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the latest advances in the molecular biology of sarcomas and their effects on clinical oncology; it is meant for a broad readership ranging from novices to experts in the field of sarcoma.

Mechanical and Non-Mechanical Functions of Filamentous and Non-Filamentous Vimentin

Intermediate filaments (IFs) formed by vimentin are less understood than their cytoskeletal partners, microtubules and F-actin, but the unique physical properties of IFs, especially their resistance to large deformations, initially suggest a mechanical function. Indeed, vimentin IFs help regulate cell mechanics and contractility, and in crowded 3D environments they protect the nucleus during cell migration. Recently, a multitude of studies, often using genetic or proteomic screenings show that vimentin has many non-mechanical functions within and outside of cells. These include signaling roles in wound healing, lipogenesis, sterol processing, and various functions related to extracellular and cell surface vimentin. Extracellular vimentin is implicated in marking circulating tumor cells, promoting neural repair, and mediating the invasion of host cells by viruses, including SARS-CoV, or bacteria such as Listeria and Streptococcus. These findings underscore the fundamental role of vimentin in not only cell mechanics but also a range of physiological functions. Also see the video abstract here https://youtu.be/YPfoddqvz-g.

HMGA1 Regulates the Stem Cell-Like Properties of Circulating Tumor Cells from GIST Patients via Wnt/β-Catenin Pathway

Background

Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the digestive system. Circulating tumor cells (CTCs) have been proven to be critical in the recurrence and metastasis of diseases; however, the characteristics of CTCs of GIST are still unclear.

Methods

We sorted out and verified the validity of CTCs from peripheral blood of gastrointestinal stromal tumor (GIST) patients with or without heterochronous liver metastasis using flow cytometry (FCM). Differential genes were analyzed between the GIST patients with and without liver metastasis using next-generation sequencing (NGS).

Results

The preliminary study on the characteristics of CTCs revealed that CTCs of GIST patients with heterochronous liver metastasis had stronger stem cell-like properties (SC-like properties) than CTCs of those without liver metastasis. Furthermore, NGS followed with a series of assays revealed that HMGA1 played a critical role in regulating the SC-like properties of CTCs. Mechanistically, HMGA1 could activate Wnt/β-catenin pathway in vitro and vivo. Moreover, we found that the expression level of HMGA1 in CTCs was an independent risk factor probably influencing the prognosis of GIST patients.

Conclusion

Our findings indicate the significant role of HMGA1 in SC-like properties, IM resistance and eventually hepatic metastasis formation of CTCs. Targeting HMGA1 in CTCs may be a therapeutic strategy for GIST patients with hepatic metastasis.

Circulating tumor cells in whole process management of gastrointestinal stromal tumor in a real-life setting

BACKGROUND/AIM

Liquid biopsy is changing the diagnosis and treatment strategies of various neoplasms. However, the circulating tumor cells (CTCs) of gastrointestinal stromal tumor (GIST) patients with different disease process are not clear. To better understand the dynamic change of CTCs in GIST patients, we conducted a real-life setting study.

PATIENTS AND METHODS

One-hundred fifty GIST patients were included. The isolation by size of tumor cell (ISET) method was employed to detect the CTCs/circulating tumor microemboli (CTM). Imatinib (IM) plasma concentration was detected by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Multivariate and univariate analysis were used to analyze the effects of clinical characteristics on the positive rate of CTC and the number of CTCs/CTM.

RESULTS

The positive rate of CTCs was 72%. The median number of CTCs and CTM was 4 and 0. Logistic multivariate regression analysis showed that tumor diameter was the only independent factor of the positive rate of CTCs (P < 0.05). The numbers of CTCs and CTM had intensive linear correlation (P < 0.001). Tumor diameter, Ki 67 expression and mitotic were related to the number of CTCs (P < 0.05). Patients with higher Ki 67 expression tend to have more CTM (P < 0.05). IM plasma concentration showed no influence to the CTCs/CTM (P > 0.05).

CONCLUSIONS

: In the current study, we assessed the CTCs and CTM of GIST patients in various disease progressions and identified clinicopathological factors influencing the detection of CTCs and CTM. These results are instructive for clinicians to understand CTCs/CTM in GIST patients.

Efficacy of a bismuth-based quadruple therapy regimen for Helicobacter pylori eradication in Saudi Arabia

BACKGROUND/AIM

The treatment efficacy of Helicobacter pylori (H. pylori) has been decreasing over time due to resistance to multiple antimicrobial therapies. The most effective treatment regimen for Saudi Arabian patients infected with H. pylori is still unknown. We aimed to study the eradication rate of 10 days of quadruple therapy; bismuth subcitrate potassium 140 mg, metronidazole 125 mg, and tetracycline 125 mg for H. pylori infection in a Saudi population.

PATIENTS AND METHODS

This was a prospective, open-label, non-randomized controlled trial. Patients with H. pylori infection were diagnosed by upper gastrointestinal (GI) endoscopy and rapid urease test (RUT) or histology. Patients who tested positive were recruited. Eligible patients were prescribed a 10-day course of quadruple therapy and received three capsules 4 times daily for 10 days along with omeprazole 20 mg twice daily. H. pylori was considered eradicated if the urea breath test (UBT) was negative after 6 weeks of completing the treatment.

RESULTS

Ninety-two patients with H. pylori infection were recruited. Three patients withdrew from the trial and another seven patients lost follow-up. We analyzed 82 patient's data as per-protocol analysis, of whom 66 (80%) were naive to H. pylori treatment. Four patients had failed previous treatment with the sequential regimen and 12 patients had treatment with clarithromycin-based triple therapy. The post-treatment UBT for H. pylori infection was negative by per-protocol analysis in 72/82 patients (87.8%), and 72/92 (78.3%) by intention-to-treat analysis. There was no correlation between previous treatment failure and treatment response to the bismuth-based quadruple therapy (P value = 0.28).

CONCLUSIONS

Treatment with a bismuth-based quadruple therapy was effective in eradicating H. pylori infection in 78.3% of Saudi patients with an ITT analysis and in 87.8% as per-protocol analysis.

The Use of Molecular Subtypes for Precision Therapy of Recurrent and Metastatic Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor in the digestive tract. Tyrosine kinase inhibitors (TKIs), represented by imatinib, sunitinib, and regorafenib, have become the main treatment for recurrent and metastatic GISTs. With the wide application of mutation analysis and the precision medicine, molecular characteristics have been determined that not only predict the prognosis of patients with recurrent and metastatic GISTs, but also are closely related to the efficacy of first-, second- and third-line TKIs for GISTs, as well as other TKIs. Despite the significant effects of TKIs, the emergence of primary and secondary resistance ultimately leads to treatment failure and tumor progression. Currently, due to the signal transmission of KIT/PDGFRA during onset and tumor progression, strategies to counteract drug resistance include the replacement of TKIs and the development of new drugs that are directed towards carcinogenic mutations. In addition, it is also the embodiment of precision medicine for GISTs to explore new carcinogenic mechanisms and develop new drugs relying on new biotechnology. Surgery can benefit specific patients but its major purpose is to diminish the resistant clones. However, the prognosis of recurrent and metastatic patients is still unsatisfactory. Therefore, it is worth paying attention to how to maximize the benefits for patients.

Prognostic significance of PD-L1 expression on cell-surface vimentin-positive circulating tumor cells in gastric cancer patients

Although circulating tumor cells (CTCs) have shown promise as potential biomarkers for diagnostic and prognostic assessment in gastric cancer (GC), determining the predictive and prognostic value of programmed death‐ligand 1 (PD‐L1)‐positive CTCs in patients with GC is a challenge. Here, we identified that the expression of total vimentin (VIM) protein was positively correlated with PD‐L1 and inhibited CD8⁺ T‐cell activation in patients with GC according to bioinformatics analysis. Notably, coexpression of PD‐L1 and cell‐surface VIM (CSV) was detected by immunofluorescence and immunohistochemistry assay in locally advanced GC tumor specimens and metastatic lymph nodes. Likewise, CSV expression level was significantly decreased after transiently knocking down PD‐L1 in GC cell lines. Based on our established CTC detection platform, CTCs were isolated from peripheral blood samples collected from 70 patients (38 resectable and 32 unresectable) with GC using magnetic positive selection and a CSV‐specific monoclonal antibody, 84‐1. CSV⁺PD‐L1⁺CTCs were observed in 50 of 70 (71%) GC patient samples, ranging from 0 to 261 mL⁻¹. A higher number of CSV⁺PD‐L1⁺CTCs were significantly associated with a short survival duration and poor therapeutic response. This study demonstrated that detection of PD‐L1⁺CTCs using a CSV‐enrichment method has promising value as a clinically relevant prognostic marker for GC.

Nanotechnology in cancer diagnosis: progress, challenges and opportunities

In the fight against cancer, early detection is a key factor for successful treatment. However, the detection of cancer in the early stage has been hindered by the intrinsic limits of conventional cancer diagnostic methods. Nanotechnology provides high sensitivity, specificity, and multiplexed measurement capacity and has therefore been investigated for the detection of extracellular cancer biomarkers and cancer cells, as well as for in vivo imaging. This review summarizes the latest developments in nanotechnology applications for cancer diagnosis. In addition, the challenges in the translation of nanotechnology-based diagnostic methods into clinical applications are discussed.

Improved Isolation of Mesenchymal Stem Cells Based on Interactions between N-Acetylglucosamine-Bearing Polymers and Cell-Surface Vimentin

Mesenchymal stem cells (MSCs) in bone marrow and adipose tissues are expected to be effective tools for regenerative medicine to treat various diseases. To obtain MSCs that possess both high differentiation and tissue regenerative potential, it is necessary to establish an isolation system that does not require long-term culture. It has previously been reported that the cytoskeletal protein vimentin, expressed on the surfaces of multiple cell types, possesses N-acetylglucosamine- (GlcNAc-) binding activity. Therefore, we tried to exploit this interaction to efficiently isolate MSCs from rat bone marrow cells using GlcNAc-bearing polymer-coated dishes. Cells isolated by this method were identified as MSCs because they were CD34-, CD45-, and CD11b/c-negative and CD90-, CD29-, CD44-, CD54-, CD73-, and CD105-positive. Osteoblast, adipocyte, and chondrocyte differentiation was observed in these cells. In total, yields of rat MSCs were threefold to fourfold higher using GlcNAc-bearing polymer-coated dishes than yields using conventional tissue-culture dishes. Interestingly, MSCs isolated with GlcNAc-bearing polymer-coated dishes strongly expressed CD106, whereas those isolated with conventional tissue-culture dishes had low CD106 expression. Moreover, senescence-associated β-galactosidase activity in MSCs from GlcNAc-bearing polymer-coated dishes was lower than that in MSCs from tissue-culture dishes. These results establish an improved isolation method for high-quality MSCs.

Current progress in the clinical use of circulating tumor cells as prognostic biomarkers

The process of metastasis is characterized by the shedding of tumor cells into the bloodstream, where they are transported to other parts of the body to seed new tumors. These cells, known as circulating tumor cells (CTCs), have the potential to reveal much about an individual cancer case, and theoretically can aid in the prediction of outcomes and design of precision treatments. Recent advances in technology now allow for the robust and reproducible characterization of CTCs from a simple blood draw. Both the number of circulating cells and important molecular characteristics correlated with clinical phenotypes such as drug resistance can be obtained and used for real-time prognostic analysis. Molecular characterization can provide a snapshot of the activity of the main tumor (serving as a "liquid biopsy") and early warnings concerning changes such as the development of resistance, and aid in predicting the efficacy of different therapeutic approaches for treatment optimization. Herein, the authors review the current clinical use of CTCs as prognostic biomarkers for several different cancers. The quantification of CTCs can lead to more accurate staging and decision making regarding options such as adjuvant chemotherapy.

A Binding Potency Assay for Pritumumab and Ecto-Domain Vimentin

Pritumumab, a natural human IgG1kappa mAb, was isolated from the regional lymph node of a patient with cervical cancer. This antibody has been reported to bind the cytoskeletal protein vimentin, and to cell surface expressed vimentin referred to as ecto-domain vimentin (EDV). Here, we report details of the development of a potency of binding assay for pritumumab as a prerequisite before pursuing clinical trials. The enzyme linked immunosorbent assay (ELISA) to detect antibody-binding antigen can serve as a potency assay for release of manufactured samples to be used in clinical studies. Several layers of controls for this assay along with suitability testing for reagents and components of the assay must be developed before the assay can be incorporated for stability testing and release of manufatured samples.