To overcome the problem of overlooking colorectal tumors, a new and highly sensitive modality of colonoscopy is needed. Moreover, it is also important to establish a new modality to evaluate viable ...tumor volume in primary lesions of colorectal cancer (CRC) during chemotherapy. Therefore, we carried out molecular imaging of colorectal tumors targeting epidermal growth factor receptor (EGFR), which is highly expressed on tumor cells, for evaluating chemotherapeutic efficacy and for endoscopic detection of colorectal adenomas. We first attempted to image five CRC cell lines with various levels of EGFR expression using an Alexa Fluor‐labeled anti‐EGFR monoclonal antibody (AF‐EGFR‐Ab). A strong fluorescence signal was observed in the cells depending on the level of EGFR expression. When nude mice xenografted with LIM1215 CRC cells, which highly express EGFR, were i.v. injected with AF‐EGFR‐Ab, a strong fluorescence signal appeared in the tumor with a high signal to noise ratio, peaking at 48 hours after injection and then gradually decreasing, as shown using an IVIS Spectrum system. When the xenografted mice were treated with 5‐fluorouracil, fluorescence intensity in the tumor decreased in proportion to the viable tumor cell volume. Moreover, when the colorectum of azoxymethane‐treated rats was observed using a thin fluorescent endoscope with AF‐EGFR‐Ab, all 10 small colorectal adenomas (≤3 mm) were detected with a clear fluorescence signal. These preliminary results of animal experiments suggest that EGFR‐targeted fluorescent molecular imaging may be useful for quantitatively evaluating cell viability in CRC during chemotherapy, and also for detecting small adenomas using a fluorescent endoscope.
Molecular imaging targeting epidermal growth factor receptor (EGFR) showed utility for evaluating therapeutic efficacy, as indicated by viable cell volume, more accurately than tumor size. This EGFR imaging method was also useful in detecting colorectal adenoma in rat colorectum. This imaging method may lead to advancements in early detection and improved diagnosis of colorectal tumors, as well as therapeutic evaluation of colorectal cancer.
It is difficult to distinguish gastrointestinal stromal tumors (GISTs) from other types of submucosal tumors under conventional gastrointestinal endoscopy. We aimed to detect GISTs by molecular ...fluorescence imaging using a near-infrared (NIR) photosensitizer (IR700)-conjugated anti-c-KIT antibody and to treat GISTs by photoimmunotherapy with NIR irradiation as a non-invasive theranostic procedure. We also investigated the therapeutic mechanisms.
Human GIST cell lines GIST-T1 and GIST-882M were incubated with IR700-conjugated anti-c-KIT antibody, IR700-12A8, and observed by confocal laser microscopy. Mice with GIST-T1 xenografts or rats with orthotopic xenografts were injected with IR700-12A8 or AF488-conjugated antibody, and observed under IVIS or autofluorescence imaging (AFI) endoscopy. GIST cells were treated with IR700-12A8 and NIR light
and vivo, and cell viability, histology and apoptosis were evaluated.
Strong red fluorescence of IR700-12A8 was observed on the cell membrane of GIST cells and was gradually internalized into the cytoplasm. Tumor-specific accumulation of IR700-12A8 was observed in GIST-T1 xenografts in mice. Under AFI endoscopy, a strong fluorescence signal was observed in orthotopic GIST xenografts in rats through the normal mucosa covering the tumor. The percentage of dead cells significantly increased in a light-dose-dependent manner and both acute necrotic and late apoptotic cell death was observed with annexin/PI staining. Cleaved PARP expression was significantly increased after IR700-12A8-mediated NIR irradiation, which was almost completely reversed by NaN
. All xenograft tumors (7/7) immediately regressed and 4/7 tumors completely disappeared after IR700-12A8-mediated NIR irradiation. Histologic assessment and TUNEL staining revealed apoptosis in the tumors.
NIR fluorescence imaging using IR700-12A8 and subsequent NIR irradiation could be a very effective theranostic technology for GIST, the underlying mechanism of which appears to involve acute necrosis and supposedly late apoptosis induced by singlet oxygen.
Nonalcoholic fatty liver disease (NAFLD) is known to be strongly associated with obesity, visceral fat, metabolic syndrome (MS), lifestyle, and lifestyle-related diseases in both males and females. ...However, the prevalence of NAFLD, MS, and clinical backgrounds is different between males and females.
We conducted a cross-sectional study to examine the differing influence of lifestyle-related factors and visceral fat on fatty liver (FL) with elevation of liver enzymes between males and females with MS.
We enrolled 42,134 persons who underwent a regular health check-up, and after excluding subjects who fulfilled excluding criteria, the remaining subjects were 2,110 persons with MS. We examined the differing influence of lifestyle-related factors and visceral fat on FL with elevation of alanine aminotransferase (ALT) (ALT elevation was defined as ALT level of ≥31 IU/l in the present study).
The odds rations for FL with ALT elevation were as follows: WC, 1.83 (95% confidence interval (CI) 1.36-2.46); dyslipidemia, 1.89 (95% CI 1.34-2.68); hemoglobin A1c, 1.36 (95% CI 1.00-1.85); visceral fat type MS (V-type MS), 5.78 (95% CI 4.29-7.80); and light drinker, 0.56 (95% CI 0.41-0.78) in males with MS and BMI, 2.18 (95% CI 1.43-3.33); WC, 1.85 (95% CI 1.27-2.70); diastolic blood pressure, 1.69 (95% CI 1.16-2.45); triglyceride, 2.22 (95% CI 1.56-3.17); impaired glucose tolerance, 1.66 (95% CI 1.11-2.47); and V-type MS, 3.83 (95% CI 2.57-5.70) in females with MS. The prevalence of FL with ALT elevation and ALT was significantly higher in V-type MS than in the subcutaneous fat type MS in both males and females with MS (P < 0.001).
Although V-type MS and WC is a common significant predictor of an increased prevalence of FL with ALT elevation in both males and females with MS, gender, lifestyle-related factors, and MS type in individuals with MS should be considered for the development of FL with ALT elevation.
A 70-year-old man with a gastric lesion was referred to our hospital because of an unusual pedunculated lesion in the gastric body. Endoscopic ultrasound showed scattered cystic lesions within a ...heterogeneous area confined to the submucosal layer. Endoscopic mucosal resection was performed to obtain a precise diagnosis, as well as for removal. The lesion was histopathologically diagnosed as a heterotopic submucosal gland. We herein describe this rare type of gastric polyp and provide a literature review.
A 29-year-old female visited a hospital because of increasingly severe lower leg edema. She was diagnosed as having multiple polyps in the stomach and colon by gastroscopy and sigmoidoscopy as well ...as multiple liver tumors by abdominal CT. She was referred to our hospital for further examination. Total colonoscopy revealed a type 2 tumor in the transverse colon and more than 200 polyps distributed throughout the colorectum. Biopsies of the tumor and polyps showed histological characteristics of adenocarcinoma and tubulovillous adenoma, respectively. Thus, she was diagnosed as having metastatic colon cancer derived from familial adenomatous polyposis (FAP). Laboratory tests showed a marked hypoalbuminemia of 1.1 g/dl. The fecal alpha-1 anti-trypsin test showed abnormal clearance (62.1 ml/day), and scintigraphy using 99mTc-human serum albumin revealed protein loss in the whole colon. Multiple ligation probe amplification analysis of the
APC
gene identified a germline duplication of exons 11–13. Direct sequencing of the reverse transcription PCR products of
APC
mRNA revealed a deletion of 25 base pairs and a tandem duplication of exons 11–13. This case was considered to be protein-losing enteropathy resulting from numerous colonic tubulovillous adenomas and advanced colon cancer in a FAP patient with unusual mutational events in
APC
.
Background and Aim
It is difficult to differentiate gastrointestinal stromal tumors (GISTs) from other subepithelial lesions under gastrointestinal endoscopy. Because most GISTs express tyrosine ...kinase receptor c‐KIT, fluorescence‐labeled c‐KIT‐specific tyrosine kinase inhibitors seem to be useful agents for molecular imaging of GIST. We aimed to develop a near‐infrared fluorescent imaging technology for GIST targeting c‐KIT using the novel fluorescent probe indocyanine green‐labeled dasatinib (ICG‐dasatinib) and to investigate the antitumor effect of ICG‐dasatinib on GIST cells.
Methods
Indocyanine green‐labeled dasatinib was synthesized by labeling linker‐induced dasatinib with ICG derivative 3‐indocyanine‐green‐acyl‐1,3‐thiazolidine‐2‐thione. Human GIST cell lines GIST‐T1 and GIST‐882M were incubated with ICG‐dasatinib and observed by fluorescent microscopy. GIST cells were incubated with ICG‐dasatinib, unlabeled dasatinib, or imatinib, and cell viabilities were evaluated. Subcutaneous GIST model mice or orthotopic GIST model rats were intravenously injected with ICG‐dasatinib and observed using an IVIS Spectrum.
Results
Strong fluorescent signals of ICG‐dasatinib were observed in both GIST cell lines in vitro. IC50 values for ICG‐dasatinib, unlabeled dasatinib, and imatinib were 13.9, 1.17, and 16.2 nM in GIST‐T1 and 26.6, 3.63, and 47.6 nM in GIST‐882M cells, respectively. ICG‐dasatinib accumulated in subcutaneous xenografts in mice. Fluorescent signals were also observed in liver and gallbladder, indicating biliary excretion; however, fluorescence intensity of tumors was significantly higher than that of intestine after washing. Strong fluorescent signals were observed in orthotopic xenografts through the covering normal mucosa in rats.
Conclusions
Indocyanine green‐labeled dasatinib could visualize GIST cells and xenografted tumors. The antitumor effect of ICG‐dasatinib was preserved to the same degree as imatinib.
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