Colorectal cancer (CRC) is one of the most daunting diseases due to its increasing worldwide prevalence, which requires imperative development of minimally or non-invasive screening tests. Urinary polyamines have been reported as potential markers to detect CRC, and an accurate pattern recognition to differentiate CRC with early stage cases from healthy controls are needed. Here, we utilized liquid chromatography triple quadrupole mass spectrometry to profile seven kinds of polyamines, such as spermine and spermidine with their acetylated forms. Urinary samples from 201 CRCs and 31 non-CRCs revealed the N1,N12-diacetylspermine showing the highest area under the receiver operating characteristic curve (AUC), 0.794 (the 95% confidence interval (CI): 0.704–0.885, p < 0.0001), to differentiate CRC from the benign and healthy controls. Overall, 59 samples were analyzed to evaluate the reproducibility of quantified concentrations, acquired by collecting three times on three days each from each healthy control. We confirmed the stability of the observed quantified values. A machine learning method using combinations of polyamines showed a higher AUC value of 0.961 (95% CI: 0.937–0.984, p < 0.0001). Computational validations confirmed the generalization ability of the models. Taken together, polyamines and a machine-learning method showed potential as a screening tool of CRC.

Hand-sewing (HS) and stapling are common parenchymal closure techniques after distal pancreatectomy. However, these methods cannot completely prevent postoperative pancreatic fistula (POPF). The mechanisms of POPF formation after closure are unknown. We performed distal pancreatectomy in mongrel dogs to identify the mechanisms of POPF formation after HS and staple closure. We measured the closed pancreatic duct burst pressures and examined the histology of the remnant pancreas. The after stapleclosure burst pressures depended on stapler height; lower pressures were associated with greater stapler heights. Post-HS closure burst pressures were significantly higher than those at each stapler height (P < 0.01). Post-HS closure pathologic findings showed extensive necrosis (day 3), and some regenerated pancreatic duct stumps (day 5). Necrosis was not observed around the stapled tissues. Although HS completely closes the pancreatic ducts, stump necrosis and blood flow disturbances may cause POPF. With stapler closure, pancreatic fluid leakage may occur even with appropriate stapler heights.

Colorectal cancer (CRC) has increasing global prevalence and poor prognostic outcomes, and the development of low- or less invasive screening tests is urgently required. Urine is an ideal biofluid that can be collected non-invasively and contains various metabolite biomarkers. To understand the metabolomic profiles of different stages of CRC, we conducted metabolomic profiling of urinary samples. Capillary electrophoresis-time-of-flight mass spectrometry was used to quantify hydrophilic metabolites in 247 subjects with stage 0 to IV CRC or polyps, and healthy controls. The 154 identified and quantified metabolites included metabolites of glycolysis, TCA cycle, amino acids, urea cycle, and polyamine pathways. The concentrations of these metabolites gradually increased with the stage, and samples of CRC stage IV especially showed a large difference compared to other stages. Polyps and CRC also showed different concentration patterns. We also assessed the differentiation ability of these metabolites. A multiple logistic regression model using three metabolites was developed with a randomly designated training dataset and validated using the remaining data to differentiate CRC and polys from healthy controls based on a panel of urinary metabolites. These data highlight the changes in metabolites from early to late stage of CRC and also the differences between CRC and polyps.

As the worldwide prevalence of colorectal cancer (CRC) increases, it is vital to reduce its morbidity and mortality through early detection. Saliva‐based tests are an ideal noninvasive tool for CRC detection. Here, we explored and validated salivary biomarkers to distinguish patients with CRC from those with adenoma (AD) and healthy controls (HC). Saliva samples were collected from patients with CRC, AD, and HC. Untargeted salivary hydrophilic metabolite profiling was conducted using capillary electrophoresis–mass spectrometry and liquid chromatography–mass spectrometry. An alternative decision tree (ADTree)‐based machine learning (ML) method was used to assess the discrimination abilities of the quantified metabolites. A total of 2602 unstimulated saliva samples were collected from subjects with CRC ( n = 235), AD ( n = 50), and HC ( n = 2317). Data were randomly divided into training ( n = 1301) and validation datasets ( n = 1301). The clustering analysis showed a clear consistency of aberrant metabolites between the two groups. The ADTree model was optimized through cross‐validation (CV) using the training dataset, and the developed model was validated using the validation dataset. The model discriminating CRC + AD from HC showed area under the receiver‐operating characteristic curves (AUC) of 0.860 (95% confidence interval [CI]: 0.828‐0.891) for CV and 0.870 (95% CI: 0.837‐0.903) for the validation dataset. The other model discriminating CRC from AD + HC showed an AUC of 0.879 (95% CI: 0.851‐0.907) and 0.870 (95% CI: 0.838‐0.902), respectively. Salivary metabolomics combined with ML demonstrated high accuracy and versatility in detecting CRC.

Abstract. Certain cell lines exhibit metastatic ability (highly metastatic cell lines) while their parent cell lines have no metastatic ability. Differences in methylation, which are not derived from differences in the gene sequence between cell lines, were extensively analyzed. Using an established highly metastatic cell line, KM12SM, and its parent cell line, KM12C, differences in the frequency of methylation were analyzed in the promoter regions of ~480,000 gene sites using Infinium HumanMethylation450. The promoter region of the Rho GTPase-activating protein 28 (ARHGAP28) gene was the most markedly methylated region in KM12SM compared with KM12C. ARHGAP28 is a GTPase-activating protein (GAP), and it converts activated RhoA to inactivated RhoA via GTPase. RhoA activity was compared between these two cell lines. The activated RhoA level was compared using western blot analysis and G-LISA. The activated RhoA level was higher in KM12SM compared to KM12C for western blot analysis and G-LISA analysis. RhoA is a protein involved in cytoskeleton formation and cell motility. RhoA, for which ARHGAP28 acts as a GAP, is possibly a factor involved in the metastatic ability of cancer. IntroductionClinical cancer lesions are masses of heterologous cancer cells. The mainstream hypothesis of cancer metastasis is that 'a population of highly malignant cells acquires metastatic ability due to the accumulation of gene mutations forming metastatic lesions' (1), i.e., it is hypothesized that highly malignant cancer cells with metastatic ability and low-malignant cancer cells with no metastatic ability are present in the same cancer lesion, and metastatic lesions are mainly formed by the former. Certain established cancer cell lines have a high metastatic ability (highly metastatic cell lines) that is similar to clinical cancers. To establish a highly metastatic cell line, an animal model of metastasis is prepared and cells collected from metastatic lesions are transplanted into another animal, and this procedure is repeated. A highly metastatic cell line is established by passaging only a cell population that has metastasized in the metastasis model, however, why such a highly malignant cell line is established from a genetically cloned cell line through this passaging method is questionable. It is unlikely that a new change in a gene sequence, such as gene mutation, occurs through only several passages even in a metastasis model. Cancer cell lines are manufactured on the assumption that cells will be passaged a specific number of times. When a gene mutation occurs within a small number of passages, this contradicts the stability of the cancer cell line. Therefore, the difference between a highly metastatic cell line and its parent cell line with no metastatic ability is of interest and we hypothesize that the difference is not a genetic mutation.Recent studies identified the presence of the alternation of cell phenotypes, termed epigenetic abnormality, in cancers, in addition to genetic mutation. The representative epigenetic ch...

Cancer cell engraftment in the target organ is necessary to establish metastasis. Clinically, lymph node metastasis of single cells has been confirmed using cytokeratin staining. In the current study, a LacZ-labeled cancer cell line was used to visualize intrahepatic metastasis of single cells or liver micrometastasis. KM12SM-lacZ stably expressing LacZ was prepared with a highly metastatic colon cancer cell line, KM12SM. KM12SM-lacZ was injected into the spleen of nude mice and following 1 week the spleen was excised. The liver was then examined for metastasis following 1, 2 or 3 weeks. Confirmation of liver metastasis was completed by observing the grade of metastasis. Grade-1 metastasis (DNA level), human DNA in liver tissue was detected; Grade-2 metastasis (metastasis of single cells), confirmed by X-gal staining; Grade-3 metastasis (histopathological micrometastasis), diagnosed by light microscopy and Grade-4 metastasis (typical metastasis), easily detected macroscopically or by hematoxylin and eosin staining. The Grade-1 metastasis detection rates 1, 2 and 3 weeks following splenectomy were 50, 100 and 100%, respectively. Grade-2 metastasis was not detected by microscopy. The Grade-3 metastasis detection rates for 1, 2 and 3 weeks were 75, 100 and 100%, respectively. Micrometastasis was observed in the portal vein lumen and wall. The Grade-4 metastasis detection rates were 50, 100 and 100% for 1, 2 and 3 weeks respectively. Cancer cells were present in vessels surrounding the main tumor. In conclusion, a specific number of cancer cell aggregates may be necessary to establish hematogenous metastasis.

Abstract. Photodynamic therapy (PDT) is a method used treat tumors via utilizing photodynamic reactions between photosensitive substances with tumor affinity and lasers. For overall bile duct cancers, PDT has been demonstrated to resolve stenosis and improve prognosis; however, when limited to intrahepatic bile duct cancers, modifications to the laser irradiation are necessary as surrounding hepatocytes incorporate a large amount of photosensitive substances. Furthermore, the intrahepatic bile duct is thin, and a guide sheath and thin fiber are necessary to transport laser irradiation probes to the target region. In the present study, a parallel-type ultra-small composite optical fiberscope (COF) with an outer diameter of 1 mm or smaller was developed to target a thin intrahepatic bile duct. PDT was performed using an animal model and talaporfin sodium (Laserphyrin), which is rapidly excreted by hepatocytes and is suitable for use with a long-wavelength laser due to its high tissue penetrating ability. The results demonstrated that Laserphyrin does not cause necrotic changes in the normal biliary tract mucosa. In addition, COF images of sufficient quality were acquired. The present results suggest that COF may be used for the treatment of deep bile duct lesions.

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