Bulk and single-cell RNA sequencing analyses coupled with multiple machine learning to develop a glycosyltransferase associated signature in colorectal cancer.

BACKGROUND: This study aims to identify key glycosyltransferases (GTs) in colorectal cancer (CRC) and establish a robust prognostic signature derived from GTs. METHODS: Utilizing the AUCell, UCell, singscore, ssgsea, and AddModuleScore algorithms, along with correlation analysis, we redefined genes related to GTs in CRC at the single-cell RNA level. To improve risk model accuracy, univariate Cox and lasso regression were employed to discover a more clinically subset of GTs in CRC. Subsequently, the efficacy of seven machine learning algorithms for CRC prognosis was assessed, focusing on survival outcomes through nested cross-validation. The model was then validated across four independent external cohorts, exploring variations in the tumor microenvironment (TME), response to immunotherapy, mutational profiles, and pathways of each risk group. Importantly, we identified potential therapeutic agents targeting patients categorized into the high-GARS group. RESULTS: In our research, we classified CRC patients into distinct subgroups, each exhibiting variations in prognosis, clinical characteristics, pathway enrichments, immune infiltration, and immune checkpoint genes expression. Additionally, we established a Glycosyltransferase-Associated Risk Signature (GARS) based on machine learning. GARS surpasses traditional clinicopathological features in both prognostic power and survival prediction accuracy, and it correlates with higher malignancy levels, providing valuable insights into CRC patients. Furthermore, we explored the association between the risk score and the efficacy of immunotherapy. CONCLUSION: A prognostic model based on GTs was developed to forecast the response to immunotherapy, offering a novel approach to CRC management.

SAFFRON-104: a phase Ib/II study of sitravatinib alone or with tislelizumab in advanced hepatocellular carcinoma and gastric cancer/gastroesophageal junction cancer.

BACKGROUND: Sitravatinib is a spectrum-selective tyrosine kinase inhibitor targeting TAM (TYRO3, AXL, MER), VEGFR-2, KIT, and MET. SAFFRON-104 (NCT03941873) was a multicohort phase Ib/II study investigating sitravatinib with/without tislelizumab, an anti-programmed cell death protein 1 (PD-1) antibody, in patients with advanced hepatocellular carcinoma (HCC) or gastric cancer/gastroesophageal junction cancer (GC/GEJC). METHODS: Eligible patients had histologically/cytologically confirmed advanced HCC or GC/GEJC. Phase I determined the recommended phase II dose (RP2D) of sitravatinib with/without tislelizumab. Phase II evaluated sitravatinib monotherapy in patients with pretreated HCC, and sitravatinib plus tislelizumab in anti-PD-(L)1-naïve or -treated HCC and anti-PD-(L)1-naïve GC/GEJC. Primary endpoints were safety/tolerability (phase I) and objective response rate (ORR) (phase II). RESULTS: At data cutoff (March 31, 2023), 111 patients were enrolled; 102 were efficacy-evaluable (median study follow-up 9.1 months [range: 0.7-36.9]). The RP2D of sitravatinib was determined as 120 mg orally once daily. In patients receiving sitravatinib monotherapy and sitravatinib in combination with tislelizumab, grade ≥ 3 treatment-related adverse events occurred in 14 (51.9%) and 42 (50.0%) patients, respectively. The ORR was 25% (95% confidence interval [CI]: 8.7-49.1) in patients with pretreated HCC receiving sitravatinib monotherapy. In patients receiving sitravatinib with tislelizumab, the ORR was 11.5% (95% CI 2.4-30.2) with anti-PD-(L)1-naïve HCC, 9.5% (95% CI 1.2-30.4) with anti-PD-(L)1-treated HCC, and 16.1% (95% CI 5.5-33.7) in patients with anti-PD-(L)1-naïve GC/GEJC. CONCLUSIONS: Sitravatinib with/without tislelizumab was generally well tolerated and showed preliminary antitumor activity in patients with advanced HCC and GC/GEJC.

Construction of a DNA walker nanomachine aptasensor for simultaneous detection of dual-cancer biomarkers.

While it is recognized that early diagnosis of cancer-related biomarkers can become an effective avenue for timely treatment and successfully improve patient survival, it remains challenging to get accurate inspection results. Currently, most reported cancer biomarker sensing methods are focused on the quantitative detection of a single type of biomarker, which makes accurate medical diagnostics difficult. In this work, we constructed a DNA walker nanomachine aptasensor based on gold nanoparticles for the simultaneous sensing of dual cancer biomarkers. The aptamers, labelled with a fluorophore, hybridized with complementary strands on the gold nanoparticle surface, serve as a walking track. Target analytes bind to their specific aptamers, leading to the dissociation of the unstable double-strand spherical nucleic acid. Exonuclease I (Exo I) selectively digested the aptamers bound with the target analytes, then the released targets go back to the next apamers on the gold nanopareticles surface for walking. The use of spherical nucleic acid probes improved the sensitivity of analyte detection. Exo I provided a driving power for target recycling and considerably improved the sensitivity of the aptasensor as well. The DNA walker nanomachine aptasensor was successfully applied for the detection of carcinoembryonic antigen (CEA) in the range of 0.167 to 3.34 ng mL-1, and mucin-1 (MUC-1) in the same range. Moreover, we used the two aptamers to construct the DNA walker nanomachine and achieved the simultaneous detection of CEA and MUC-1, thus having great potential for biomolecular logic gate construction and early disease diagnosis.

Ultra-sensitive detection of SARS-CoV-2 S1 protein by coupling rolling circle amplification with poly(N-isopropylacrylamide)-based sandwich-type assay.

In the past few years, the COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) seriously threatens global public health security due to its high contagiousness. It remains of vital importance to develop a rapid and sensitive assay for SARS-CoV-2. In this work, we proposed a sandwich-type assay based on poly(N-isopropylacrylamide) (PNIPAM), allowing efficient detection of the SARS-CoV-2 S1 protein in the homogeneous solution. Firstly, a direct sandwich-type assay was established with a linear range of 0.2-2 µg/mL and a limit of detection (LOD) of 0.11 µg/mL, which could realize rapid detection in about 1 h. Furthermore, the sandwich-type assay coupled with rolling circle amplification (RCA) obtained an increase in sensitivity of 5.9 × 104 folds with a wide linear range of 0.01 - 100 ng/mL and a LOD of 1.88 pg/mL. The average recoveries in unpretreated saliva were 90 %-113.0 %, indicating the potential of the developed method for application in practical samples. Given the high selectivity and sensitivity of the developed method, it has a significant potential for rapid and early detection of SARS-CoV-2.

Fruquintinib plus paclitaxel versus placebo plus paclitaxel for gastric or gastroesophageal junction adenocarcinoma: the randomized phase 3 FRUTIGA trial.

The vascular endothelial growth factor pathway plays a key role in the pathogenesis of gastric cancer. In the multicenter, double-blind phase 3 FRUTIGA trial, 703 patients with advanced gastric or gastroesophageal junction adenocarcinoma who progressed on fluorouracil- and platinum-containing chemotherapy were randomized (1:1) to receive fruquintinib (an inhibitor of vascular endothelial growth factor receptor-1/2/3; 4 mg orally, once daily) or placebo for 3 weeks, followed by 1 week off, plus paclitaxel (80 mg/m2 intravenously on days 1/8/15 per cycle). The study results were positive as one of the dual primary endpoints, progression-free survival (PFS), was met (median PFS, 5.6 months in the fruquintinib arm versus 2.7 months in the placebo arm; hazard ratio 0.57; 95% confidence interval 0.48-0.68; P < 0.0001). The other dual primary endpoint, overall survival (OS), was not met (median OS, 9.6 months versus 8.4 months; hazard ratio 0.96, 95% confidence interval 0.81-1.13; P = 0.6064). The most common grade ≥3 adverse events were neutropenia, leukopenia and anemia. Fruquintinib plus paclitaxel as a second-line treatment significantly improved PFS, but not OS, in Chinese patients with advanced gastric or gastroesophageal junction adenocarcinoma and could potentially be another treatment option for these patients. ClinicalTrials.gov registration: NCT03223376 .

Exploring the Molecular Mechanism of Comorbidity of Type 2 Diabetes Mellitus and Colorectal Cancer: Insights from Bulk Omics and Single-Cell Sequencing Validation.

The relationship between type 2 diabetes mellitus (T2DM) and colorectal cancer (CRC) has long been extensively recognized, but their crosstalk mechanisms based on gene regulation remain elusive. In our study, for the first time, bulk RNA-seq and single-cell RNA-seq data were used to explore the shared molecular mechanisms between T2DM and CRC. Moreover, Connectivity Map and molecular docking were employed to determine potential drugs targeting the candidate targets. Eight genes (EVPL, TACSTD2, SOX4, ETV4, LY6E, MLXIPL, ENTPD3, UGP2) were identified as characteristic comorbidity genes for T2DM and CRC, with EVPL and ENTPD3 further identified as core comorbidity genes. Our results demonstrated that upregulation of EVPL and downregulation of ENTPD3 were intrinsic molecular features throughout T2DM and CRC and were significantly associated with immune responses, immune processes, and abnormal immune landscapes in both diseases. Single-cell analysis highlighted a cancer-associated fibroblast (CAF) subset that specifically expressed ENTPD3 in CRC, which exhibited high heterogeneity and unique tumor-suppressive features that were completely different from classical cancer-promoting CAFs. Furthermore, ENTPD3+ CAFs could notably predict immunotherapy response in CRC, holding promise to be an immunotherapy biomarker at the single-cell level. Finally, we identified that droperidol may be a novel drug simultaneously targeting EVPL and ENTPD3. In conclusion, previous studies have often focused solely on metabolic alterations common to T2DM and CRC. Our study establishes EVPL and ENTPD3 as characteristic molecules and immune biomarkers of comorbidity in T2DM and CRC patients, and emphasizes the importance of considering immunological mechanisms in the co-development of T2DM and CRC.

TPP1 is associated with risk of advanced precursors and cervical cancer survival.

It is unclear how telomere-binding protein TPP1 interacts with human telomerase reverse transcriptase (hTERT) and influences cervical cancer development and progression. This study included all eligible 156 cervical cancers diagnosed during 2003-2008 and followed up through 2014, 102 cervical intraepithelial neoplasia (CIN) patients, and 16 participants with normal cervix identified at the same period. Correlation of expression of TPP1 and hTERT in these lesions was assessed using Kappa statistics. TPP1 was knocked down by siRNA in three cervical cancer cell lines. We assessed mRNA expression using quantitative real-time polymerase chain reaction and protein expression using tissue microarray-based immunohistochemical staining. We further analyzed the impact of TPP1 expression on the overall survival of cervical cancer patients by calculating the hazard ratio (HR) with 95% confidence intervals (CIs) using the multivariable-adjusted Cox regression model. Compared to the normal cervix, high TPP1expression was significantly associated with CIN 3 and cervical cancers (P<0.001 for both). Expressions of TPP1 and hTERT were highly correlated in CIN 3 (Kappa statistics = 0.50, P = 0.005), squamous cell carcinoma (Kappa statistics = 0.22, P = 0.011), and adenocarcinoma/adenosquamous carcinoma (Kappa statistics = 0.77, P = 0.001). Mechanistically, knockdown of TPP1 inhibited the expression of hTERT in both mRNA and protein levels. High expression of TPP1 (HR = 2.61, 95% CI 1.23-5.51) and co-high expression of TPP1 and hTERT (HR = 2.38, 95% CI 1.28-4.43) were independently associated with worse survival in cervical cancer patients. TPP1 and hTERT expression was correlated and high expression of TPP1 was associated with high risk of CIN 3 and cervical cancer and could predict a worse survival in cervical cancer.

PD-1/CD80+ small extracellular vesicles from immunocytes induce cold tumours featured with enhanced adaptive immunosuppression.

Only a minority of cancer patients benefit from immune checkpoint blockade therapy. Sophisticated cross-talk among different immune checkpoint pathways as well as interaction pattern of immune checkpoint molecules carried on circulating small extracellular vesicles (sEV) might contribute to the low response rate. Here we demonstrate that PD-1 and CD80 carried on immunocyte-derived sEVs (I-sEV) induce an adaptive redistribution of PD-L1 in tumour cells. The resulting decreased cell membrane PD-L1 expression and increased sEV PD-L1 secretion into the circulation contribute to systemic immunosuppression. PD-1/CD80+ I-sEVs also induce downregulation of adhesion- and antigen presentation-related molecules on tumour cells and impaired immune cell infiltration, thereby converting tumours to an immunologically cold phenotype. Moreover, synchronous analysis of multiple checkpoint molecules, including PD-1, CD80 and PD-L1, on circulating sEVs distinguishes clinical responders from those patients who poorly respond to anti-PD-1 treatment. Altogether, our study shows that sEVs carry multiple inhibitory immune checkpoints proteins, which form a potentially targetable adaptive loop to suppress antitumour immunity.

The potential of machine learning models to identify malnutrition diagnosed by GLIM combined with NRS-2002 in colorectal cancer patients without weight loss information.

BACKGROUND & AIMS: The key step of the Global Leadership Initiative on Malnutrition (GLIM) is nutritional risk screening, while the most appropriate screening tool for colorectal cancer (CRC) patients is yet unknown. The GLIM diagnosis relies on weight loss information, and bias or even failure to recall patients' historical weight can cause misestimates of malnutrition. We aimed to compare the suitability of several screening tools in GLIM diagnosis, and establish machine learning (ML) models to predict malnutrition in CRC patients without weight loss information. METHODS: This multicenter cohort study enrolled 4487 CRC patients. The capability of GLIM diagnoses combined with four screening tools in predicting survival probability was compared by Kaplan-Meier curves, and the most accurate one was selected as the malnutrition reference standard. Participants were randomly assigned to a training cohort (n = 3365) and a validation cohort (n = 1122). Several ML approaches were adopted to establish models for predicting malnutrition without weight loss data. We estimated feature importance and reserved the top 30% of variables for retraining simplified models. The area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity were calculated to assess and compare model performance. RESULTS: NRS-2002 was the most suitable screening tool for GLIM diagnosis in CRC patients, with the highest hazard ratio (1.59; 95% CI, 1.43-1.77). A total of 2076 (46.3%) patients were malnourished diagnosed by GLIM combined with NRS-2002. The simplified random forest (RF) model outperformed other models with an AUC of 0.830 (95% CI, 0.805-0.854), and accuracy, sensitivity and specificity were 0.775, 0.835 and 0.742, respectively. We deployed an online application based on the simplified RF model to accurately estimate malnutrition probability in CRC patients without weight loss information (https://zzuwtt1998.shinyapps.io/dynnomapp/). CONCLUSIONS: Nutrition Risk Screening 2002 was the optimal initial nutritional risk screening tool in the GLIM process. The RF model outperformed other models, and an online prediction tool was developed to properly identify patients at high risk of malnutrition.

Target-induced DNA nanomachine operation for the detection of proteins.

Accurate and sensitive detection of disease-associated proteins in early stage of patients plays an important role in timely treatment and successfully extending patients' lives. To meet this demand, we herein rationally designed a flexible target-induced DNA nanomachine operation (TIDNMO) sensor for the detection of proteins. The TIDNMO system was composed of DNA nanoswitch and DNA walker. Triplex DNA nanoswitch was triggered by specific target, followed by the release of the walking strand, which initiated the DNA walker amplification as signal output. In addition, the Exo III could drive walking strand autonomously move on gold nanoparticle surface to realize 2 orders of magnitude signal amplification. What's more, this sensor could transform its suitable functional recognition element of DNA nanoswitch to recognize other specific molecule and realize different targets sensing based on identical walking tracks. Considering the facile reporter elements and efficient amplification performance, the present DNA nanomachine as a sensor could achieve a detection limit of 68 pM for anti-Dig antibody, 0.95 pM for mucin-1 respectively, along with a superb specificity. Furthermore, the method reported here opened a new chapter in disease-related protein sensing for the development of clinical early diagnosis.

Therapy-induced senescent tumor cell-derived extracellular vesicles promote colorectal cancer progression through SERPINE1-mediated NF-κB p65 nuclear translocation.

BACKGROUND: Cellular senescence frequently occurs during anti-cancer treatment, and persistent senescent tumor cells (STCs) unfavorably promote tumor progression through paracrine secretion of the senescence-associated secretory phenotype (SASP). Extracellular vesicles (EVs) have recently emerged as a novel component of the SASP and primarily mediate the tumor-promoting effect of the SASP. Of note, the potential effect of EVs released from STCs on tumor progression remains largely unknown. METHODS: We collected tumor tissues from two cohorts of colorectal cancer (CRC) patients to examine the expression of p16, p21, and SERPINE1 before and after anti-cancer treatment. Cohort 1 included 22 patients with locally advanced rectal cancer (LARC) who received neoadjuvant therapy before surgical resection. Cohort 2 included 30 patients with metastatic CRC (mCRC) who received first-line irinotecan-contained treatment. CCK-8, transwell, wound-healing assay, and tumor xenograft experiments were carried out to determine the impacts of EVs released from STCs on CRC progression in vitro and in vivo. Quantitative proteomic analysis was applied to identify protein cargo inside EVs secreted from STCs. Immunoprecipitation and mass spectrometer identification were utilized to explore the binding partners of SERPINE1. The interaction of SERPINE1 with p65 was verified by co-immunoprecipitation, and their co-localization was confirmed by immunofluorescence. RESULTS: Chemotherapeutic agents and irradiation could potently induce senescence in CRC cells in vitro and in human CRC tissues. The more significant elevation of p16 and p21 expression in patients after anti-cancer treatment displayed shorter disease-free survival (DFS) for LARC or progression-free survival (PFS) for mCRC. We observed that compared to non-STCs, STCs released an increased number of EVs enriched in SERPINE1, which further promoted the progression of recipient cancer cells. Targeting SERPINE1 with a specific inhibitor, tiplaxtinin, markedly attenuated the tumor-promoting effect of STCs-derived EVs. Additionally, the patients with greater increment of SERPINE1 expression after anti-cancer treatment had shorter DFS for LARC or PFS for mCRC. Mechanistically, SERPINE1 bound to p65, promoting its nuclear translocation and subsequently activating the NF-κB signaling pathway. CONCLUSIONS: We provide the in vivo evidence of the clinical prognostic implications of therapy-induced senescence. Our results revealed that STCs were responsible for CRC progression by producing large amounts of EVs enriched in SERPINE1. These findings further confirm the crucial role of therapy-induced senescence in tumor progression and offer a potential therapeutic strategy for CRC treatment.

Bifidobacterium modulation of tumor immunotherapy and its mechanism.

The advent of tumor immunotherapy in patients has revolutionized the treatment of tumors and significantly improved survival rates for a wide range of tumors. However, the full therapeutic potential of immune checkpoint inhibitors (ICIs) has yet to be realized, as not all patients have a lasting survival benefit from them, and a significant proportion of patients show primary or acquired resistance to immunotherapy. Bifidobacterium is one of the most common probiotics, and its antitumor and immunomodulatory effects have been demonstrated in recent years, but its immunomodulatory effects in tumors, especially on ICIs and in combination, have not been extensively studied in clinical practice, and its effects on the immune system and the mechanisms that modulate immunotherapy are largely unknown. Therefore, this review will focus on the immunomodulatory effects of Bifidobacteria in malignancies and the possible mechanisms of action of Bifidobacteria on immunotherapy in the hope of providing a basis for further research and better application of Bifidobacteria in clinical practice.

A simple, rapid and sensitive sandwich immunoassay based on poly(N-isopropylacrylamide) for the detection of alpha-fetoprotein.

Alpha-fetoprotein (AFP), as a tumor marker, plays a vital role in the diagnosis of liver cancer. In this work, a novel sandwich immunoassay based on a thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), was developed for the detection of AFP. This immunoassay could realize one-step rapid reaction within 1 h, and facilitate the separation of the target molecules by incorporating PNIPAM. In this method, a conjugate of PNIPAM and capture antibody (Ab1) was successfully synthesized as a capture probe and the synthetic method of PNIPAM-Ab1 was simple, while the detection antibody (Ab2) was labeled with fluorescein isothiocyanate (FITC) to form a fluorescent detection probe. By employing a sandwich immunoassay, the method achieved quantitative determination of AFP, exhibiting a wide linear range from 5 ng/mL to 200 ng/mL and a low detection limit of 2.44 ng/mL. Furthermore, it was successfully applied to the analysis of spiked human serum samples and the screening of patients with hepatic diseases in clinical samples, indicating its potential application prospect in the diagnosis of liver cancer.

Case report: Resolution of Guillain-Barré syndrome in a patient with dual primary tumors after treatment with rituximab.

Guillain-Barré syndrome (GBS) is a rare immune-related adverse event (irAE) that can occur in solid tumors such as hepatocellular carcinoma, gastric cancer, breast cancer, and colorectal cancer. It is characterized by progressive myasthenia and mild sensory abnormalities. The emergence of immune checkpoint inhibitors (ICIs) has significantly improved cancer patients' life expectancy but can also trigger various irAEs, including GBS. We report a rare case of GBS in a 64-year-old male patient with dual primary tumors of the colon and stomach who received toripalimab and chemotherapy for liver metastases. After five treatments, the patient experienced weakness and numbness in his limbs. Lumbar puncture, electromyography, and other tests confirmed the diagnosis of GBS. Intravenous immunoglobulin (IVIG) and methylprednisolone did not improve the patient's symptoms, but rituximab, which is not a standard regimen for GBS, was effective in eliminating B cells and improving symptoms. Following this, we effectively shifted from a regimen combining immunotherapy and chemotherapy to a targeted therapy regimen, resulting in prolonged patient survival. Currently, limited studies have been undertaken to evaluate the efficacy of rituximab in managing refractory neurological adverse events associated with ICI therapy. Using this case, we reviewed similar cases and formed our views.

Integrated neutrophil-to-lymphocyte ratio and handgrip strength better predict survival in patients with cancer cachexia.

OBJECTIVES: Systemic inflammation and skeletal muscle strength play crucial roles in the development and progression of cancer cachexia. In this study we aimed to evaluate the combined prognostic value of neutrophil-to-lymphocyte ratio (NLR) and handgrip strength (HGS) for survival in patients with cancer cachexia. METHODS: This multicenter cohort study involved 1826 patients with cancer cachexia. The NLR-HGS (NH) index was defined as the ratio of neutrophil-to-lymphocyte ratio to handgrip strength. Harrell's C index and receiver operating characteristic (ROC) curve analysis were used to assess the prognosis of NH. Kaplan-Meier analysis and Cox regression models were used to evaluate the association of NH with all-cause mortality. RESULTS: Based on the optimal stratification, 380 women (NH > 0.14) and 249 men (NH > 0.19) were classified as having high NH. NH has shown greater predictive value compared to other indicators in predicting the survival of patients with cancer cachexia according to the 1-, 3-, and 5-y ROC analysis and Harrell's C index calculation. Multivariate survival analysis showed that higher NH was independently associated with an increased risk of death (hazard ratio = 1.654, 95% confidence interval = 1.389-1.969). CONCLUSION: This study demonstrates that the NH index, in combination with NLR and HGS, is an effective predictor of the prognosis of patients with cancer cachexia. It can offer effective prognosis stratification and guidance for their treatment.

Value of the modified Patient-Generated Subjective Global Assessment in indicating the need for nutrition intervention and predicting overall survival in patients with malignant tumors in at least two organs.

BACKGROUND: Although the Patient-Generated Subjective Global Assessment (PG-SGA) is a reference standard used to assess a patient's nutrition status, it is cumbersome to administer. The aim of the present study was to estimate the value of a simpler and easier-to-use modified PG-SGA (mPG-SGA) to evaluate the nutrition status and need for intervention in patients with malignant tumors present in at least two organs. METHODS: A total of 591 patients (343 male and 248 female) were included from the INSCOC study. A Pearson correlation analysis was conducted to assess the correlation between the mPG-SGA and nutrition-related factors, with the optimal cut-off defined by a receiver operating characteristic curve (ROC). The consistency between the mPG-SGA and PG-SGA was compared in a concordance analysis. A survival analysis was used to determine the effects of nutritional intervention among different nutrition status groups. Univariable and multivariable Cox analyses were applied to evaluate the association of the mPG-SGA with the all-cause mortality. RESULTS: The mPG-SGA showed a negative association with nutrition-related factors. Individuals with an mPG-SGA ≥ 5 (rounded from 4.5) were considered to need nutritional intervention. Among the malnourished patients (mPG-SGA ≥ 5), the overall survival (OS) of those who received nutrition intervention was significantly higher than that of patients who did not. However, the OS was not significantly different in the better-nourished patients (mPG-SGA < 5). CONCLUSION: Our findings support that the mPG-SGA is a feasible tool that can be used to guide nutritional interventions and predict the survival of patients with malignant tumors affecting at least two organs.

A Facile Strategy for Multiplex Protein Detection by a Fluorescent Microsphere-Based Digital Immunoassay.

The digital immunoassay is a highly sensitive detection technique based on single-molecule counting and is widely used in the ultrasensitive detection of biomarkers. Herein, we developed a fluorescent microsphere-based digital immunoassay (FMDIA) by employing fluorescent microspheres as both the carriers for immunoreaction and fluorescent reports for imaging. In this approach, the target protein in the sample was captured by fluorescent microspheres to form a biotin-labeled sandwich immunocomplex, and then, the fluorescent microspheres containing the target protein molecules were captured by adding streptavidin-coated magnetic beads (SA-MBs). By counting the proportion of fluorescence-positive magnetic beads, the concentration of the target protein can be precisely quantified. As a proof of concept, α fetoprotein (AFP) and human interleukin-6 (IL-6) were used to assess the analytical performance of the proposed FMDIA, and limit of detection (LOD) values of 21 pg/mL (0.30 pM) and 0.19 pg/mL (7.3 fM) were achieved, respectively. The results of AFP detection in serum samples of patients and healthy people were consistent with the reference values given by the hospital. Furthermore, by adding fluorescent microspheres of various colors for encoding, the proposed FMDIA can easily realize the simultaneous detection of multiple proteins without the need to introduce multiple modified magnetic beads. This multiplex protein detection strategy, in which the reactions are first carried out on the fluorescent microspheres and then magnetic beads are used to capture the fluorescent reporters containing the target molecules, provides a new idea for digital assays.

Amplification-free detection of Mpox virus DNA using Cas12a and multiple crRNAs.

Mpox virus (MPXV) is a zoonotic DNA virus that caused human Mpox, leading to the 2022 global outbreak. MPXV infections can cause a number of clinical syndromes, which increases public health threats. Therefore, it is necessary to develop an effective and reliable method for infection prevention and control of epidemic. Here, a Cas12a-based direct detection assay for MPXV DNA is established without the need for amplification. By targeting the envelope protein gene (B6R) of MPXV, four CRISPR RNAs (crRNAs) are designed. When MPXV DNA is introduced, every Cas12a/crRNA complex can target a different site of the same MPXV gene. Concomitantly, the trans-cleavage activity of Cas12a is triggered to cleave the DNA reporter probes, releasing a fluorescence signal. Due to the application of multiple crRNAs, the amount of active Cas12a increases. Thus, more DNA reporter probes are cleaved. As a consequence, the detection signals are accumulated, which improves the limit of detection (LOD) and the detection speed. The LOD of the multiple crRNA system can be improved to ~ 0.16 pM, which is a decrease of the LOD by approximately ~ 27 times compared with the individual crRNA reactions. Furthermore, using multiple crRNAs increases the specificity of the assay. Given the outstanding performance, this assay has great potential for Mpox diagnosis.