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.

Design, synthesis and biological evaluation of 1,2,3-triazole benzothiazole derivatives as tubulin polymerization inhibitors with potent anti-esophageal cancer activities.

In this work, we utilized the molecular hybridization strategy to design and synthesize novel 1,2,3-triazole benzothiazole derivatives K1-26. The antiproliferative activities against MGC-803, Kyse30 and HCT-116 cells were explored, and their structure-activity relationship were preliminarily conducted and summarized. Among them, compound K18, exhibited the strongest proliferation inhibitory activity, with esophageal cancer cells Kyse30 and EC-109 being the most sensitive to its effects (IC50 values were 0.042 and 0.038 µM, respectively). Compound K18 effectively inhibited tubulin polymerization (IC50 = 0.446 µM), thereby hindering tubulin polymerize into filamentous microtubules in Kyse30 and EC-109 cells. Additionally, compound K18 induced the degradation of oncogenic protein YAP via the UPS pathway. Based on these dual molecular-level effects, compound K18 could induce G2/M phase arrest and cell apoptosis in Kyse30 and EC-109 cells, as well as regulate the expression levels of cell cycle and apoptosis-related proteins. In summary, our findings highlight a novel 1,2,3-triazole benzothiazole derivative K18, which possesses significant potential for treating esophageal cancers.

Annual review of PROTAC degraders as anticancer agents in 2022.

Following nearly two decades of development, significant advancements have been achieved in PROTAC technology. As of the end of 2022, more than 20 drugs have entered clinical trials, with ARV-471 targeting estrogen receptor (ER) showing remarkable progress by entering phase III clinical studies. In 2022, significant progress has been made on multiple targets. The first reversible covalent degrader designed to target the KRASG12C mutant protein, based on cyclopropionamide, has been reported. Additionally, the activity HDCA1 degrader surpassed submicromolar levels during the same year. A novel FEM1B covalent ligand called EN106 was also discovered, expanding the range of available ligands. Furthermore, the first PROTAC drug targeting SOS1 was reported. Additionally, the first-in-class degraders that specifically target BRD4 isoforms (BRD4 L and BRD4 S) have recently been reported, providing a valuable tool for further investigating the biological functions of these isoforms. Lastly, a breakthrough was also achieved with the first degrader targeting both CDK9 and Cyclin T1. In this review, we aimed to update the PROTAC degraders as potential anticancer agents covering articles published in 2022. The design strategies, degradation effects, and anticancer activities were highlighted, which might provide an updated sight to develop novel PROTAC degraders with great potential as anticancer agents as well as favorable drug-like properties.

A novel antigenic epitope identified on the accessory protein NS6 of porcine deltacoronavirus.

Porcine deltacoronavirus (PDCoV) is a novel enteric coronavirus that can cause vomiting, watery diarrhea in pigs and the death of piglets. The open reading frame (ORF) 5 is one of the accessory genes in PDCoV genome and encodes an accessory protein NS6. To date, the function of NS6 is still unclear. In this study, the recombinant NS6 was successfully expressed in prokaryotic expression system and purified. To prepare monoclonal antibody (mAb), six-week-old female BALB/c mice were primed subcutaneously with purified NS6. A novel mouse mAb against NS6 was obtained and designated as 3D5. The isotype of 3D5 is IgG2b with kappa (κ) light chain. 3D5 can specifically recognizes the natural NS6 in swine testis (ST) cells infected with PDCoV and expressed NS6 in human embryonic kidney 293T (HEK 293T) cells transfected with mammalian vector. The minimal linear B cell epitope recognised by 3D5 on NS6 was 25VPELIDPLVK34 determined by peptide scanning and named EP-3D5. The sequence of EP-3D5 is completely conserved among PDCoV strains. Moreover, six to nine residues of EP-3D5 were identified to be conserved in non-PDCoV strains. These results provide valuable insights into the antigenic structure and function of NS6 in virus pathogenesis, and aid for the development of PDCoV epitope-associated diagnostics and vaccine design.

Design, synthesis and biological evaluation of novel 2,4-diaminopyrimidine cinnamyl derivatives as inhibitors of FAK with potent anti-gastric cancer activities.

In this study, twenty-one novel 2,4-diaminopyrimidine cinnamyl derivatives as inhibitors targeting FAK were designed and synthesized based on the structure of TAE-226, and the inhibitory effects of these compounds on both the FAK enzyme and three cancer cell lines (MGC-803, HCT-116, and KYSE30) were investigated. Among them, compound 12s displayed potent inhibitory potency on FAK (IC50 = 47 nM), and demonstrated more significant antiproliferative activities in MGC-803, HCT-116 and KYSE30 cells (IC50 values were 0.24, 0.45 and 0.44 µM, respectively) compared to TAE-226. Furthermore, compound 12s significantly inhibited FAK activation leading to the negative regulation of FAK-related signaling pathways such as AKT/mTOR and MAPK signaling pathways. Molecular docking study suggested that compound 12s could well occupy the ATP-binding pocket site of FAK similar to TAE-226. In addition, compound 12s also efficiently inhibited the proliferation, induced apoptosis and cellular senescence in MGC-803 cells. In conclusion, compound 12s emerges a potent FAK inhibitor that could exert potent inhibitory activity against gastric cancer cells.

Chaetoglobosin E inhibits tumor growth and promotes the anti-tumor efficacy of cytotoxic drugs in esophageal squamous cell carcinoma by targeting PLK1.

Background: Currently, there is no satisfactory treatment available for esophageal squamous cell carcinoma (ESCC), and thus, there is a pressing need to develop effective drugs. Chaetoglobosin E, a cytochalasan alkaloid derived from metabolites of Chaetomium madrasense 375, is a chaetoglobosin with intense anti-tumor activity. Therefore, revealing its anti-tumor mechanism for the application of cytochalasans is crucial. Methods: The cytotoxic effect of chaetoglobosin E and cisplatin on esophageal cancer KYSE-30, KYSE-150, and TE-1 cells was detected using cell viability or colony formation assays. The cell cycle, apoptosis, autophagy, invasion, and metastasis were assayed by flow cytometry or western blot. The potential target of chaetoglobosin E was assayed by RNA sequencing (RNA-seq) and large loop prediction software analysis and was assessed by western blot and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The effect of its target on cell pyroptosis was assayed using overexpression and silence experiments. Results: Chaetoglobosin E significantly inhibited the proliferation of KYSE-30, KYSE-150, and TE-1 cells, especially KYSE-30 cells. Our results showed that chaetoglobosin E induced the G2/M phase arrest of KYSE-30 cells, followed by the down-regulation of cyclinB1, CDC2, and p-CDC2, and up-regulation of p21. Moreover, chaetoglobosin E also decreased the anti-apoptotic protein expression of Bcl-2, increased apoptotic expression of Bax, increased autophagy protein expressions of beclin1 and LC3, decreased invasion and metastasis protein expression of E-cadherin, and increased expression of vimentin. The RNA-seq and large loop prediction software analysis results indicated that its potential target might be polo-like kinase 1 (PLK1). Moreover, results also showed that chaetoglobosin E can reverse the PLK1 overexpression plasmid-induced up-regulation of the PLK1 protein. Furthermore, we found that chaetoglobosin E induced pyroptosis via the activation of the gasdermin E (GSDME) protein. Further studies showed that the high expression of PLK1 inactivated the GSDME protein, while the knockdown of PLK1 expression activated the GSDME protein, indicating that chaetoglobosin E induced cell pyroptosis by inhibiting PLK1. Conclusions: This study suggested that chaetoglobosin E may be a novel lead compound to the treatment of ESCC patients by targeting PLK1, and elucidated for the first time that PLK1 was involved in a new pyroptosis mechanism.

Circulating tumor cells and neutrophil-lymphocyte ratio are predictive markers for metastatic colorectal cancer patients.

BACKGROUND: More accurate predictive factors for colorectal cancer (CRC) are urgently needed. This study aimed to assess the potential prognostic roles of circulating tumor cells (CTCs), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) in CRC patients. METHODS: Between 2014 and 2017, 118 CRC patients newly diagnosed at the Affiliated Zhongshan Hospital of Dalian University were retrospectively analyzed, including 72 (61%) patients that underwent radical resection (resectable CRC) and 46 (39%) advanced patients with metastatic CRC (mCRC). The CellSearch System was used to detect CTCs, and Spearman's correlation analyses tested the correlations between CTC counts and both NLR and PLR. Statistical analyses were performed using the Kaplan-Meier method, log-rank tests, and Cox proportional hazards models. RESULTS: Of the resectable cohort, 24% were positive for CTCs. Of the advanced cohort, 49% were positive for CTCs. The presence of CTCs was associated with advanced age (≥63 years old; P=0.037), a high PLR value (P=0.008), and a high NLR value (P=0.034). Additionally, baseline NLR [hazard ratio (HR) =0.423; 95% confidence intervals (CI), 0.223-0.803; P=0.008], PLR (HR =0.513; 95% CI, 0.276-0.954; P=0.035), and CTC counts (HR =2.155; 95% CI, 1.152-4.032; P=0.016) were significantly associated with progression-free survival (PFS) in a univariate analysis of mCRC patients that received chemotherapy. Multivariate analysis further showed that NLR (P=0.044) and CTCs (P=0.047) were independent prognostic factors for mCRC patients. CONCLUSIONS: This study provided evidence that NLR and CTC counts could serve as robust prognostic factors for patients with mCRC.

Radiation induces epithelial to mesenchymal transition via upregulation of PD-L1 in nasopharyngeal carcinoma cell.

BACKGROUND: The acquisition of radioresistance by nasopharyngeal carcinoma (NPC) cells during radiotherapy may lead to tumor metastasis and poor survival. This study aimed to explore the mechanism of long-term radiation-induced NPC metastasis. METHODS: The radioresistant NPC cell, Hone-1R, was established for further study. A colony-forming assay was selected for the evaluation of radioresistant capacity, while a scratch wound healing assay was used to detect tumor cell migration. The expression of relative protein levels were detected by Western blot (WB) analysis and immunofluorescence. Cell morphology was acquired by microscopy. The programmed cell death ligand-1 (PD-L1) expression level in NPC tumor tissues was evaluated based on the publicly available datasets of NPC patients. RESULTS: A radioresistant NPC cell, Hone-1R, was established with a total dose of 180 Gy, and verified by radioresistant capacity testing. The morphology of Hone-1R cells showed obvious mesenchymal-like cells. WB and wound healing assays indicated that Hone-1R cells exhibited an epithelial-mesenchymal transition (EMT) phenotype with high migration ability and upregulation of PD-L1. Knockdown of PD-L1 reversed EMT status and reduced the migration ability of Hone-1R cells. Further analysis indicated that PD-L1 was overexpressed in more advanced stages and was positively correlated with the EMT score in NPC patients based on in silico analysis. CONCLUSIONS: Our study revealed that long-term radiation induces EMT and increases migration ability of NPC radioresistant cells through upregulation of PD-L1. These results advance our investigation of the underlying mechanism of ionizing radiation (IR)-induced migration, and suggest potential interventions to reverse EMT-induced acquisition of radioresistance in NPC.

A porcine epidemic diarrhea virus strain with distinct characteristics of four amino acid insertion in the COE region of spike protein.

In recent years, a novel, highly virulent variant of porcine epidemic diarrhea virus (PEDV) has emerged, causing substantial economic losses to the pork industry worldwide. In this study, a PEDV strain named LNsy was successfully isolated in China. Phylogenetic analysis based on the whole genome revealed that PEDV LNsy belonged to the G2 subtype. For the first time, a unique four amino acids (4-aa) insertion was identified in the COE region of the spike (S) protein (residues 499-640), resulting in an extra alpha helix in the spatial structure of the COE region. To determine changes in virus-neutralization (VN) antibody reactivity of the virus, polyclonal antibodies (PAbs) against the S protein of different subtypes were used in a VN test. Both PAbs against the S protein of the G1 and G2 subtype showed reduced VN reactivity to PEDV LNsy. Further, recombination analyses revealed that PEDV LNsy was the result of recombination between PEDV GDS13 and GDS46 strains at the genomic breakpoints (nt 17,959-20,594 in the alignment) in the ORF1b gene of the genomes. Pathological examination showed gross morphological pathological changes in the gut, including significant villus atrophy and shedding of the infected piglets. These results indicated that a 4-aa insertion in the COE region of the S protein may have partly altered the profiles of VN antibodies and thus it will be important to develop vaccine candidates to resist wild virus infection and to monitor the genetic diversity of PEDV.

Molecular characterization of an emerging reassortant mammalian orthoreovirus in China.

Mammalian orthoreoviruses (MRVs) infect almost all mammals, and there are some reports on MRVs in China. In this study, a novel strain was identified, which was designated as HLJYC2017. The results of genetic analysis showed that MRV HLJYC2017 is a reassortant strain. According to biological information analysis, different serotypes of MRV contain specific amino acid insertions and deletions in the σ1 protein. Neutralizing antibody epitope analysis revealed partial cross-protection among MRV1, MRV2, and MRV3 isolates from China. L3 gene recombination in MRV was identified for the first time in this study. The results of this study provide valuable information on MRV reassortment and evolution.

Development of an indirect ELISA for detecting porcine deltacoronavirus IgA antibodies.

Porcine deltacoronavirus (PDCoV) is a novel coronavirus that can cause vomiting and watery diarrhea in pigs and death in piglets. Since PDCoV was first detected in 2009 in Hong Kong, the prevalence of PDCoV has increased in recent years, resulting in serious economic losses to the swine industry. The coronavirus spike (S) protein is an antigen that has been demonstrated to contain epitopes that induce neutralizing antibodies. The presence of serum and milk IgA antibodies against pathogens that replicate primarily on mucosal surfaces is important for mucosal immunity. Here, an indirect anti-PDCoV IgA antibody enzyme-linked immunosorbent assay (PDCoV S1 IgA ELISA) using the purified S1 portion of S protein as the coating antigen was developed to detect PDCoV IgA antibodies in serum and sow's milk. A receiver operating characteristic (ROC) curve analysis showed high specificity and sensitivity of the PDCoV-S1-IgA-ELISA based on samples confirmed by IFA. Anti-PDCoV IgA antibodies in 152 serum samples and 65 milk samples collected from six farms that had experienced diarrhea outbreaks within previous last two years were detected by this assay, and 62.5% of the serum samples and 100% of the milk samples were positive for PDCoV. The indirect ELISA method established in this study will provide a convenient tool for measurement of serum and milk IgA levels against PDCoV in pig herds, rapid detection of PDCoV infection in pigs, and evaluation of the immunogenicity of vaccines.

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.

The prognostic role of a combined fibrinogen and inflammation-based index in patients with metastatic breast cancer.

BACKGROUND: The activation of inflammation and coagulation cascades plays an essential role in the development of various malignancies, including metastatic breast cancer (MBC). This retrospective study aimed to investigate the prognostic role of the combination of fibrinogen and the inflammation-based index in patients with MBC. METHODS: A total of 176 patients with MBC were retrospectively reviewed. The clinical and pathological data of included patients were followed-up and analyzed. The plasma fibrinogen concentration (FIB), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) were measured. Dynamic variations in the FIB, NLR, and PLR values were collected from 56 MBC patients before and after first-line therapy. Receiver operating characteristic (ROC) curves were constructed to assess the optimal cut-off values. Correlations between FIB and NLR or PLR were evaluated using Spearman correlation analysis. The Kaplan-Meier method, two-tailed log-rank test, and Cox proportional hazard model were used for statistical analysis. RESULTS: Baseline FIB was positively correlated with NLR and PLR values in MBC patients (P<0.05). Additionally, multivariable analysis proved that the ERBB2 + subtype (P=0.023), basal-like subtype (P=0.032), targeted therapy (P=0.033), other regimens (P=0.005), and baseline FIB level (P=0.004) were independent prognostic variables for progression-free survival (PFS) in MBC patients. Furthermore, ERBB2+, basal-like subtypes, and baseline hyperfibrinogenemia were independent factors for poor prognosis in MBC patients [hazard ratio (HR): 3.717, 95% confidence interval (CI): 1.561-8.851, P=0.003; HR: 3.245, 95% CI: 1.368-7.698, P=0.008; HR: 2.069, 95% CI: 1.352-3.167, P=0.001, respectively]. Most importantly, the FIB level increased significantly after first-line therapy in patients with disease progression (3.73±0.63 vs. 5.32±0.52 g/L, P=0.042) and also decreased markedly in stable disease (3.42±1.05 vs. 3.03±0.73 g/L, P=0.036). However, PFS and overall survival (OS) were not significantly correlated with the dynamic changes of FIB and the inflammation-based index. CONCLUSIONS: The present study provided evidence that baseline FIB combined with NLR and PLR could serve as prognostic predictors for MBC patients. Dynamic change of FIB before and after first-line therapy could also be used as a potential predictor of therapeutic response in MBC patients.