Efficiency of Gastrointestinal Cancer Detection by Nematode-NOSE (N-NOSE)

A non-invasive screening method using Caenorhabditis elegans for early detection of multiple cancer types: A prospective clinical study

Cancer is the second leading cause of death worldwide, according to the World Health Organization, surpassed only by cardiovascular diseases. Early identification and intervention can significantly improve outcomes. However, finding a universal, non-invasive, economical, and precise method for early cancer detection remains a significant challenge. This study explores the efficacy of an innovative cancer detection test, N-NOSE, leveraging a Caenorhabditis elegans olfactory assay on urine samples across a diverse patient group exceeding 1600 individuals diagnosed with various cancers, with samples from the Shikoku Cancer Center (Ehime, Japan) under approved ethical standards. Current cancer screening techniques often require invasive procedures, can be painful or complex, with poor performance, and might be prohibitively costly, limiting accessibility for many. N-NOSE addresses these challenges head-on by offering a test based on urine analysis, eliminating the need for invasive methods, and being more affordable with higher performance at early stages than extensive blood tests or comprehensive body scans for cancer detection. In this study, N-NOSE demonstrated a capability to accurately identify upwards of 20 cancer types, achieving detection sensitivities between 60 and 90 %, including initial-stage cancers. The findings robustly advocate for N-NOSE's potential as a revolutionary, cost-effective, and minimally invasive strategy for broad-spectrum early cancer detection. It is also particularly significant in low- and middle-income countries with limited access to advanced cancer diagnostic methods, which may contribute to the improved outcome of affected individuals.

Worm-Based Diagnosis Combining Microfluidics toward Early Cancer Screening

Early cancer diagnosis increases therapy efficiency and saves huge medical costs. Traditional blood-based cancer markers and endoscopy procedures demonstrate limited capability in the diagnosis. Reliable, non-invasive, and cost-effective methods are in high demand across the world. Worm-based diagnosis, utilizing the chemosensory neuronal system of C. elegans, emerges as a non-invasive approach for early cancer diagnosis with high sensitivity. It facilitates effectiveness in large-scale cancer screening for the foreseeable future. Here, we review the progress of a unique route of early cancer diagnosis based on the chemosensory neuronal system of C. elegans. We first introduce the basic procedures of the chemotaxis assay of C. elegans: synchronization, behavior assay, immobilization, and counting. Then, we review the progress of each procedure and the various cancer types for which this method has achieved early diagnosis. For each procedure, we list examples of microfluidics technologies that have improved the automation, throughput, and efficiency of each step or module. Finally, we envision that microfluidics technologies combined with the chemotaxis assay of C. elegans can lead to an automated, cost-effective, non-invasive early cancer screening technology, with the development of more mature microfluidic modules as well as systematic integration of functional modules.

Cell-free DNA methylation profiles enable early detection of colorectal and gastric cancer

Colorectal cancer (CRC) and gastric cancer (GC) rank the top five common and lethal cancers worldwide. Early detection can significantly reduce the mortality of CRC and GC. However, current clinical screening methods including invasive endoscopic techniques and noninvasive fecal occult blood test screening tests/fecal immunochemical test have shown low sensitivity or unsatisfactory patient's compliance. Aberrant DNA methylation occurs frequently in tumorigenesis and cell-free DNA (cfDNA) methylation has shown the potential in multi-cancer detection. Herein, we aimed to explore the value of cfDNA methylation in the gastrointestinal cancer detection and develop a noninvasive method for CRC and GC detection. We applied targeted methylation sequencing on a total of 407 plasma samples from patients diagnosed with CRC, GC, and noncancerous gastrointestinal benign diseases (Non-Ca). By analyzing the methylation profiles of 34 CRC, 62 GC and 107 Non-Ca plasma samples in the training set (n=203), we identified 40,110 gastrointestinal cancer-specific markers and 63 tissue of origin (TOO) prediction markers. A new integrated model composed of gastrointestinal cancer detection and TOO prediction for three types of classification of CRC, GC and Non-Ca patients was further developed through logistic regression algorithm and validated in an independent validation set (n=103). The model achieved overall sensitivities of 83% and 81.3% at specificities of 81.5% and 80% for identifying gastrointestinal cancers in the test set and validation set, respectively. The detection sensitivities for GC and CRC were respectively 81.4% and 83.3% in the cohort of the test and validation sets. Among these true positive cancer samples, further TOO prediction showed accuracies of 95.8% and 95.8% for GC patients and accuracies of 86.7% and 93.3% for CRC patients, in test set and validation set, respectively. Collectively, we have identified novel cfDNA methylation biomarkers for CRC and GC detection and shown the promising potential of cfDNA as a noninvasive gastrointestinal cancer detection tool.

Pancreatic Cancer and Detection Methods

The pancreas is a vital organ with exocrine and endocrine functions. Pancreatitis is an inflammation of the pancreas caused by alcohol consumption and gallstones. This condition can heighten the risk of pancreatic cancer (PC), a challenging disease with a high mortality rate. Genetic and epigenetic factors contribute significantly to PC development, along with other risk factors. Early detection is crucial for improving PC outcomes. Diagnostic methods, including imagining modalities and tissue biopsy, aid in the detection and analysis of PC. In contrast, liquid biopsy (LB) shows promise in early tumor detection by assessing biomarkers in bodily fluids. Understanding the function of the pancreas, associated diseases, risk factors, and available diagnostic methods is essential for effective management and early PC detection. The current clinical examination of PC is challenging due to its asymptomatic early stages and limitations of highly precise diagnostics. Screening is recommended for high-risk populations and individuals with potential benign tumors. Among various PC screening methods, the N-NOSE plus pancreas test stands out with its high AUC of 0.865. Compared to other commercial products, the N-NOSE plus pancreas test offers a cost-effective solution for early detection. However, additional diagnostic tests are required for confirmation. Further research, validation, and the development of non-invasive screening methods and standardized scoring systems are crucial to enhance PC detection and improve patient outcomes. This review outlines the context of pancreatic cancer and the challenges for early detection.

The neglected potential of invertebrates in detecting disease via olfaction

Agents that cause disease alter the cell metabolism of their hosts. Cells with an altered metabolism produce particular profiles of biomolecules, which are different from those of healthy cells. Such differences may be detected by olfaction. Historically, physicians used olfactory cues to diagnose sickness by smelling the breath or the urine of patients. However, other species have been shown to possess excellent olfactory abilities. Dogs, for instance, have been frequently used as biodetectors of human diseases, including cancer, viral and bacterial infections. Other mammalian species, such as rats, have been trained to perform similar tasks, but their disease detection abilities remain poorly explored. Here, we focus on the overlooked potential of invertebrate species and we review the current literature on olfactory detection of diseases by these animals. We discuss the possible advantages of exploring further the abilities of invertebrates as detection tools for human disease.

Ability of animals to detect cancer odors

The olfactory capacity of animals has long been used by humans to help with various activities, e.g., hunting, detecting mines, locating people, and diagnosing diseases. Cancer is among the leading diseases causing death worldwide. Several recent studies have underscored the benefit of using scent to detect cancer, and this paper will review the studies using animals to detect tumor scents. A large variety of animals have been used for this purpose-dogs, rodents, insects, and nematodes-and have shown their capacity to detect cancer, with a success rate close to 90%. Here we discuss these studies, their methodologies, and the animal models used. Finally, we discuss the medical perspectives for cancer diagnosis using odors.

Gastric cancer detection by non-blood-based liquid biopsies: A systematic review looking into the last decade of research

Gastric cancer (GC) screening is arguable in most Western countries. Liquid biopsies are a great promise to answer the unmet need for less invasive diagnostic biomarkers in GC. Thus, we aimed at systematically reviewing the current knowledge on liquid biopsy-based biomarkers in GC screening. A systematic search on PubMed/MEDLINE and Scopus databases was performed on published articles reporting the use of non-blood specimen (saliva, gastric juice [GJ], urine and stool) on GC diagnosis. 3208 records were retrieved by June 2022. After removal of duplicate records, 2379 abstracts were screened, and 84 full texts included in this systematic review. More than 90% of studies were reported on Asian populations. Overall, 9 studies explored stool-, 12 saliva-, and 29 urine-derived biomarkers for GC detection. Additionally, 37 studies, representing the majority, analyzed GJ, focusing on nucleic acid molecules. Several miRNAs and lncRNA molecules have been associated with GC risk, particularly miR-21 (area under the curve [AUC] = 0.97, 95% CI: 0.94-1.00). Considering salivary biomarkers, the best described model in validation sets included the soybean agglutinin and Vicia villosa agglutinin lectins (AUC = 0.89, 95% CI: 0.80-0.99). Most studies in urine carried out metabolomic approaches, with two discriminatory models presenting AUC values superior to 0.97. This systematic review emphasizes the potential role of non-blood-based biomarkers, although further validation, particularly in Western countries, is mandatory, namely for non-invasive screening and/or monitoring, as well as the use of GJ as a tool to enhance upper gastrointestinal endoscopy accuracy.

C. elegans as a Powerful Tool for Cancer Screening

Regular cancer screening is critical for early cancer detection. Cancer screening tends to be burdensome, invasive, and expensive, especially for a comprehensive multi-organ check. Improving the rate and effectiveness of routine cancer screenings remain a challenge in health care. Multi-cancer early detection (MCED) is an exciting concept and a potentially effective solution for addressing current issues with routine cancer screening. In recent years, several technologies have matured for MCED, such as identifying cell-free tumor DNA in blood or using organisms such as Caenorhabditis elegans as a tool for early cancer detection. In Japan, N-NOSE is a commercially available multi-cancer detection test based on the chemotaxis of C. elegans using a urine sample showing 87.5% sensitivity and 90.2% specificity. In this review, we focus on using C. elegans as a powerful biosensor for universal cancer screening. We review N-NOSE clinical research results, spotlighting it as an effective primary cancer screening test.

Nematode-Applied Technology for Human Tumor Microenvironment Research and Development

Nematodes, such as Caenorhabditis elegans, have been instrumental to the study of cancer. Recently, their significance as powerful cancer biodiagnostic tools has emerged, but also for mechanism analysis and drug discovery. It is expected that nematode-applied technology will facilitate research and development on the human tumor microenvironment. In the history of cancer research, which has been spurred by numerous discoveries since the last century, nematodes have been important model organisms for the discovery of cancer microenvironment. First, microRNAs (miRNAs), which are noncoding small RNAs that exert various functions to control cell differentiation, were first discovered in C. elegans and have been actively incorporated into cancer research, especially in the study of cancer genome defects. Second, the excellent sense of smell of nematodes has been applied to the diagnosis of diseases, especially refractory tumors, such as human pancreatic cancer, by sensing complex volatile compounds derived from heterogeneous cancer microenvironment, which are difficult to analyze using ordinary analytical methods. Third, a nematode model system can help evaluate invadosomes, the phenomenon of cell invasion by direct observation, which has provided a new direction for cancer research by contributing to the elucidation of complex cell–cell communications. In this cutting-edge review, we highlight milestones in cancer research history and, from a unique viewpoint, focus on recent information on the contributions of nematodes in cancer research towards precision medicine in humans.

Scent test using Caenorhabditis elegans to screen for early-stage pancreatic cancer

Although early detection and diagnosis are indispensable for improving the prognosis of patients with pancreatic cancer, both have yet to be achieved. Except for pancreatic cancer, other cancers have already been screened through scent tests using animals or microorganisms, including Caenorhabditis elegans. While such a method may greatly improve the prognosis of pancreatic cancer, no studies have investigated the same, mainly given the difficulty of collecting suitable samples from patients with early-stage pancreatic cancer. In this study, we organized a nationwide study group comprising high-volume centers throughout Japan to collect patients with very-early-stage pancreatic cancer (stage 0 or IA). We initially performed an open-label study involving 83 cases (stage 0–IV), with subsequent results showing significant differences after surgical removal in stage 0–IA (×10 dilution: p < 0.001; ×100 dilution: p < 0.001). Thereafter, a blinded study on 28 cases (11 patients with stage 0 or IA disease and 17 healthy volunteers) was conducted by comparing very-early-stage pancreatic cancer patients with healthy volunteers to determine whether C. elegans could detect the scent of cancer for the diagnosis of early-stage pancreatic cancer. Preoperative urine samples had a significantly higher chemotaxis index compared to postoperative samples in patients with pancreatic cancer [×10 dilution: p < 0.001, area under the receiver operating characteristic curve (AUC) = 0.845; ×100 dilution: p < 0.001, AUC = 0.820] and healthy volunteers (×10 dilution: p = 0.034; ×100 dilution: p = 0.088). Moreover, using the changes in preoperative and postoperative chemotaxis index, this method had a higher sensitivity for detecting early pancreatic cancer compared to existing diagnostic markers. The clinical application C. elegans for the early diagnosis of cancer can certainly be expected in the near future.

Root-knot nematode chemotaxis is positively regulated by l-galactose sidechains of mucilage carbohydrate rhamnogalacturonan-I

Root-knot nematodes (RKNs) are plant parasites and major agricultural pests. RKNs are thought to locate hosts through chemotaxis by sensing host-secreted chemoattractants; however, the structures and properties of these attractants are not well understood. Here, we describe a previously unknown RKN attractant from flaxseed mucilage that enhances infection of Arabidopsis and tomato, which resembles the pectic polysaccharide rhamnogalacturonan-I (RG-I). Fucose and galactose sidechains of the purified attractant were found to be required for attractant activity. Furthermore, the disaccharide α-l-galactosyl-1,3-l-rhamnose, which forms the linkage between the RG-I backbone and galactose sidechains of the purified attractant, was sufficient to attract RKN. These results show that the α-l-galactosyl-1,3-l-rhamnose linkage in the purified attractant from flaxseed mucilage is essential for RKN attraction. The present work also suggests that nematodes can detect environmental chemicals with high specificity, such as the presence of chiral centers and hydroxyl groups.

Caenorhabditis elegans as a Diagnostic Aid for Pancreatic Cancer

OBJECTIVES

Early detection of pancreatic cancer is notoriously difficult. A novel cancer diagnostic method using the ability of nematodes to detect odor of urine samples has been developed (N-NOSE). This method has a high sensitivity and specificity for various cancers; however, it has not yet been verified in pancreatic cancer. We examined the usefulness of this method to aid early diagnosis of pancreatic cancer in a cancer center.

METHODS

We collected urine samples and clinical data from patients hospitalized in our division, between July 2017 and February 2019. We excluded patients with a known current or past history of other cancers. We investigated the relationship between the results of N-NOSE and the presence of pancreatic cancer.

RESULTS

There were 95 noncancer cases and 104 pancreatic cancer cases. The sensitivity and specificity of N-NOSE for pancreatic cancer were 84.6% (88/104) and 60% (57/95), respectively. N-NOSE was able to detect stages 0 to I pancreatic cancer and had a higher correlation with early-stage pancreatic cancer than advanced stage.

CONCLUSIONS

N-NOSE has sufficient sensitivity and specificity for use in clinical practice, and it holds great potential as a diagnostic aid for pancreatic cancer, especially for early-stage pancreatic cancer.

Accuracy evaluation of the C. elegans cancer test (N-NOSE) using a new combined method

Early cancer detection is critical for effective treatment. N-NOSE (Nematode-NOSE) is a simple, inexpensive, and highly sensitive cancer screening method based on the chemotaxis of the nematode Caenorhabditis elegans, which shows evasive action from the urine of healthy individuals while being attracted to the urine of cancer patients. Initially, N-NOSE relied on chemotaxis indexes obtained with 10-fold dilutions of urine samples. However, cancer tissue size and concentrations of cancer odors differ among cancer patients. In this study, we examined the accuracy improvement of N-NOSE method by using two types of dilutions, 10-fold and 100-fold. We have conducted N-NOSE tests with urine samples from 32 cancer patients (esophageal, gastric, colorectal, gallbladder, cholangiocarcinoma, breast, malignant lymphoma, and acute myeloid leukemia) along with 143 healthy subjects. Our data showed a significant difference in the N-NOSE at 10-fold dilution between the two groups (p < 0.0001), with an area under the ROC curve (AUC) of 0.9188 based on receiver operating characteristic (ROC) analysis. N-NOSE index at 100-fold dilutions was also significantly different between the two groups (p < 0.0001), with an AUC of 0.9032 based on ROC analysis. In this clinical study, we further improve N-NOSE with a combined method of two dilutions (10-fold and 100-fold) of urine samples, which results in a markedly improvement in cancer detection sensitivity of 87.5%. N-NOSE sensitivity improvement was significantly high even for early-stage cancer detection, which is in stark contrast with the sensitivity of detection using blood tumor markers (CEA, CA19-9 and CA15-3). These results strongly suggest that the N-NOSE test by this new combined method strikes a good balance between sensitivity and specificity.

A Caenorhabditis elegans behavioral assay distinguishes early stage prostate cancer patient urine from controls

Current methods for non-invasive prostate cancer (PrCa) detection have a high false-positive rate and often result in unnecessary biopsies. Previous work has suggested that urinary volatile organic compound (VOC) biomarkers may be able to distinguish PrCa cases from benign disease. The behavior of the nematode Caenorhabditis elegans has been proposed as a tool to take advantage of these potential VOC profiles. To test the ability of C. elegans Bristol N2 to distinguish PrCa cases from controls, we performed chemotaxis assays using human urine samples collected from men screened for PrCa. Behavioral response of nematodes towards diluted urine from PrCa cases was compared to response to samples from cancer-free controls. Overall, we observed a significant attraction of young adult-stage C. elegans nematodes to 1:100 diluted urine from confirmed PrCa cases and repulsion of C. elegans to urine from controls. When C. elegans chemotaxis index was considered alongside prostate-specific antigen levels for distinguishing cancer from cancer-free controls, the accuracy of patient classification was 81%. We also observed behavioral attraction of C. elegans to two previously reported VOCs to be increased in PrCa patient urine. We conclude nematode behavior distinguishes PrCa case urine from controls in a dilution-dependent manner.

Summary: The nematode Caenorhabditis elegans shows behavioral attraction to urine from prostate cancer patients, but not to controls, and this phenomenon may be a useful tool for designing diagnostic assays or biomarker discovery.

Efficacy of Analytical Technologies in Metabolomics Studies of the Gastrointestinal Cancers

According to the reports of the World Health Organization and the International Agency for Research on Cancer, cancer is the second leading cause of human death worldwide. However, early-stage detection of cancers can efficiently enhance the chance of therapy and saving lives. Metabolomics strategies apply a variety of approaches to discover new potential diagnoses, prognoses, and/or therapeutic biomarkers of various diseases. Metabolomics aims to identify and measure different low-molecular-weight biomolecules in physiological environments. In these studies, special metabolites are extracted from biological samples and identified using analytical techniques. Afterward, using data processing programs discovering significantly associated biomarkers is pursued. In the present review, we aimed to discuss recently reported analytical approaches on the metabolomics studies of gastrointestinal cancers including gastric, colorectal, and esophageal cancers. The gas- and liquid-chromatography with different detectors have been shown that are the main analytical techniques and for metabolites quantification, nuclear magnetic resonance has been utilized as a master method.

State-of-the-Art Technology of Model Organisms for Current Human Medicine

Since the 1980s, molecular biology has been used to investigate medical field mechanisms that still require the use of crude biological materials in order to achieve their necessary goals. Transcription factor-induced pluripotent stem cells are used in regenerative medicine to screen drugs and to support lost tissues. However, these cells insufficiently reconstruct whole organs and require various intact cells, such as damaged livers and diabetic pancreases. For efficient gene transfer in medical use, virally mediated gene transfers are used, although immunogenic issues are investigated. To obtain efficient detective and diagnostic power in intractable diseases, biological tools such as roundworms and zebrafish have been found to be useful for high-throughput screening (HST) and diagnosis. Taken together, this biological approach will help to fill the gaps between medical needs and novel innovations in the field of medicine.