Improved Recovery of Exfoliated Colonocytes from Feces Using Newly Developed Immunomagnetic Beads

We demonstrated the feasibility of a new methodology for isolating colonocytes from feces. To reduce costs and improve the recovery rate of colonocytes from feces, we attempted to develop new immunomagnetic beads. Several sizes of magnetic beads were prepared and tagged with a monoclonal antibody against EpCAM. We made several new monoclonal antibodies against EpCAM, and each monoclonal antibody was tagged to the magnetic beads. In the simulation, the most efficient recovery of HT-29 cells was obtained using the smallest size of beads. Also, beads tagged with a monoclonal antibody with a higher affinity against EpCAM had a higher recovery rate. Similar results were obtained when the smallest size of beads with the highest-affinity monoclonal antibody was applied to clinical samples. The newly developed immunomagnetic beads may be useful for isolating colorectal cancer cells from feces, enabling the cytological or molecular biological diagnosis of CRC

Systematic Review of Patient-Derived Xenograft Models for Preclinical Studies of Anti-Cancer Drugs in Solid Tumors

Patient-derived xenograft (PDX) models are used as powerful tools for understanding cancer biology in PDX clinical trials and co-clinical trials. In this systematic review, we focus on PDX clinical trials or co-clinical trials for drug development in solid tumors and summarize the utility of PDX models in the development of anti-cancer drugs, as well as the challenges involved in this approach, following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Recently, the assessment of drug efficacy by PDX clinical and co-clinical trials has become an important method. PDX clinical trials can be used for the development of anti-cancer drugs before clinical trials, with their efficacy assessed by the modified response evaluation criteria in solid tumors (mRECIST). A few dozen cases of PDX models have completed enrollment, and the efficacy of the drugs is assessed by 1 × 1 × 1 or 3 × 1 × 1 approaches in the PDX clinical trials. Furthermore, co-clinical trials can be used for personalized care or precision medicine with the evaluation of a new drug or a novel combination. Several PDX models from patients in clinical trials have been used to assess the efficacy of individual drugs or drug combinations in co-clinical trials

イムノビーズ ニ ヨル ベンチュウ ダイチョウ ガン サイボウ ノ ブンリ ト ダイチョウ ガン シンダン ジツヨウカ ケンキュウ

大腸癌の死亡者数は全悪性腫瘍のうち上位を占め日本でも年々増加しているが、早期に発見し内視鏡的切除や外科的切除による治療が行われれば生存率は極めて良好である。現在、大腸癌検診法として便潜血反応検査が広く普及しているが、便中の微量なヘモグロビンを診断するものであり大腸癌を特異的に診断してはいない。以前我々はepithelial cell adhesion molecule (EpCAM) 抗体が結合した磁気ビーズ（イムノビーズ）を用いて自然排泄便から癌細胞を回収する方法を報告した。そこで本研究では便分離細胞を用いた新しい大腸癌検診法の開発を目的とした

microRNA analysis of colorectal cancer using fecal and tissue samples: DOI: 10.14800/rd.1592

Recently, several microRNAs (miRNAs) have been reported as promising biomarkers for cancer detection and tumor recurrence risk. Due to its stability, miRNA can be accessed from samples stored in severe conditions, such as feces or formalin-fixed paraffin-embedded (FFPE) tissue. Fecal miRNA extracted from the residuum of fecal occult blood tests (FOBTs) was assessed to determine whether a combination of this fecal miRNA test (FmiRT) with FOBT could improve the false-negative rate of colorectal cancer (CRC) screening compared with FOBT alone. Expression of miR-106a in patients with both positive and negative FOBTs was significantly higher than in healthy volunteers. To identify a high-risk group for recurrence, miRNAs were extracted from FFPE samples of patients with stage II CRC. Tumor recurrence occurred at a significantly higher rate in patients with increased miR-181c expression than in those with lower expression. The recurrence rate in patients with stage II CRC with higher expression of miR-181c was similar to that of patients with stage III CRC who had been treated by surgical resection alone. As miRNAs are stable in several severe storage conditions, such as in fecal and FFPE samples, they could be valuable, accessible biomarkers for CRC, for use both in cancer screening and as predictors of recurrence

Development of Antibody–Drug Conjugates Using DDS and Molecular Imaging

Antibody-drug conjugate (ADC), as a next generation of antibody therapeutics, is a combination of an antibody and a drug connected via a specialized linker. ADC has four action steps: systemic circulation, the enhanced permeability and retention (EPR) effect, penetration within the tumor tissue, and action on cells, such as through drug delivery system (DDS) drugs. An antibody with a size of about 10 nm has the same capacity for passive targeting as some DDS carriers, depending on the EPR effect. In addition, some antibodies are capable of active targeting. A linker is stable in the bloodstream but should release drugs efficiently in the tumor cells or their microenvironment. Thus, the linker technology is actually a typical controlled release technology in DDS. Here, we focused on molecular imaging. Fluorescent and positron emission tomography (PET) imaging is useful for the visualization and evaluation of antibody delivery in terms of passive and active targeting in the systemic circulation and in tumors. To evaluate the controlled release of the ADC in the targeted area, a mass spectrometry imaging (MSI) with a mass microscope, to visualize the drug released from ADC, was used. As a result, we succeeded in confirming the significant anti-tumor activity of anti-fibrin, or anti-tissue factor-ADC, in preclinical settings by using DDS and molecular imagin

Mass spectrometry imaging for early discovery and development of cancer drugs

A drug delivery system (DDS) is a method for delivering a drug to its site of action in the body, with the goal of achieving therapeutic benefits while reducing adverse effects. Pharmacokinetics (PK) and pharmacodynamics (PD) studies have been conducted to evaluate drug delivery, but these approaches are rarely used in the early stages of drug discovery and development. We demonstrated that the tumor stromal barrier inhibits drug distribution within tumor tissue, especially in refractory cancers such as pancreatic cancer. This poses an obstacle to the discovery of new drugs, and is difficult to overcome using conventional in vitro drug discovery methods. In addition, we are also developing new DDS drugs and antibody-drug conjugates (ADCs). These agents act via four steps: Systemic circulation, the enhanced permeability and retention (EPR) effect, penetration within the tumor tissue, and action on cells including controlled drug release. Most of these activities can be evaluated by conventional biological or pharmacological assays. However, it is difficult to examine drug distribution and controlled drug release within targeted tissues. Recent advances in mass spectrometry imaging (MSI) allow examining drug delivery much more conveniently with the off-labeling. A mass microscope, a new type of matrix-associated laser desorption/ionization (MALDI)-MSI analyzer, is a microscope coupled with an atmospheric MALDI and quadruple ion trap time-of-flight (TOF) mass spectrometer, and can provide imaging data with enhanced resolution and high sensitivity. Using a mass microscope, we succeeded in visualizing the EPR effect of a polymeric micelle drug and controlled drug release by an ADC. Currently, we are developing a new drug imaging method using electrospray ionization (ESI)-MSI. Here, we review the use of MSI in early stages of drug discovery and development, as well as our related recent work

Mutation analysis of <it>Rad18 </it>in human cancer cell lines and non small cell lung cancer tissues

Abstract Background Genetic instability is known as a cause of oncogenesis. Though Rad18 is reported to function in a post replication mismatch repair system, the relation between the status of Rad18 and human tumorigenesis has not been described so far. Methods Mutation analysis of 34 human cancer cell lines and 32 non small cell lung cancer (NSCLC) tissues were performed by RT-PCR SSCP. Expression level of Rad18 was measured by real time RT-PCR. Stable transfectant was constructed for in vitro study. Results No mutation was found in both cancer cell lines and NSCLC tissues. A single nucleotide polymorphism (SNP) at codon 302 was detected in 51.5% of the cell lines and 62.5% of NSCLC tissues. Interestingly, Rad18 was homozygously deleted in a pulmonary adenocarcinoma cell line PC3. Furthermore, there was no difference in the expression level of wild type Rad18 and Rad18 with SNP. The growth, cell morphology, sensitivity to anti-cancer drugs and in vitro DNA repair activity between wild type Rad18 and Rad18 with SNP revealed to have no difference in vitro. Conclusion Though the frequency of SNP was tended to be higher in NSCLC patients than healthy volunteers (57.7%), as the difference was not significant, we have concluded that there is no relation between Rad18 SNP and lung cancer development.</p

Mutation analysis of Rad18 in human cancer cell lines and non small cell lung cancer tissues

BACKGROUND: Genetic instability is known as a cause of oncogenesis. Though Rad18 is reported to function in a post replication mismatch repair system, the relation between the status of Rad18 and human tumorigenesis has not been described so far. METHODS: Mutation analysis of 34 human cancer cell lines and 32 non small cell lung cancer (NSCLC) tissues were performed by RT-PCR SSCP. Expression level of Rad18 was measured by real time RT-PCR. Stable transfectant was constructed for in vitro study. RESULTS: No mutation was found in both cancer cell lines and NSCLC tissues. A single nucleotide polymorphism (SNP) at codon 302 was detected in 51.5% of the cell lines and 62.5% of NSCLC tissues. Interestingly, Rad18 was homozygously deleted in a pulmonary adenocarcinoma cell line PC3. Furthermore, there was no difference in the expression level of wild type Rad18 and Rad18 with SNP. The growth, cell morphology, sensitivity to anti-cancer drugs and in vitro DNA repair activity between wild type Rad18 and Rad18 with SNP revealed to have no difference in vitro. CONCLUSION: Though the frequency of SNP was tended to be higher in NSCLC patients than healthy volunteers (57.7%), as the difference was not significant, we have concluded that there is no relation between Rad18 SNP and lung cancer development