EL4 Murine-Lymphoma-Stromal-Cell Fusion Hybrids Observed With Multiple Distinct Morphologies in the Primary Tumor and Metastatic Organs of a Syngeneic Mouse Model.

BACKGROUND/AIM: We and others have previously shown that cell fusion plays an important role in cancer metastasis. Color coding of cancer and stromal cells with spectrally-distinct fluorescent proteins is a powerful tool, as pioneered by our laboratory to detect cell fusion. We have previously reported color-coded cell fusion between cancer cells and stromal cells in metastatic sites by using color-coded EL4 murine lymphoma cells and host mice expressing spectrally-distinct fluorescent proteins. Cell fusion occurred between cancer cells or, between cancer cells and normal cells, such as macrophages, fibroblasts, and mesenchymal stem cells. In the present study, the aim was to morphologically classify the fusion-hybrid cells observed in the primary tumor and multiple metastases EL4 formed from cells expressing red fluorescent protein (RFP) in transgenic mice expressing green fluorescent protein (GFP), in a syngeneic model. MATERIALS AND METHODS: RFP-expressing EL4 murine lymphoma cells were cultured in vitro. EL4-RFP cells were harvested and injected intraperitoneally into immunocompetent transgenic C57/BL6-GFP mice to establish a syngeneic model. Two weeks later, mice were sacrificed and each organ was harvested, cultured, and observed using confocal microscopy. RESULTS: EL4 intraperitoneal tumors (primary) and metastases in the lung, liver, blood, and bone marrow were formed. All tumors were harvested and cultured. In all specimens, RFP-EL4 cells, GFP-stromal cells, and fused yellow-fluorescent hybrid cells were observed. The fused hybrid cells showed various morphologies. Immune cell-like round-shaped yellow-fluorescent fused cells had a tendency to decrease with time in liver metastases and circulating blood. In contrast fibroblast-like spindle-shaped yellow-fluorescent fused cells increased in the intraperitoneal primary tumor, lung metastases, and bone marrow. CONCLUSION: Cell fusion between EL4-RFP cells and GFP stromal cells occurred in primary tumors and all metastatic sites. The morphology of the fused hybrid cells varied in the primary and metastatic sites. The present results suggest that fused cancer and stromal hybrid cells of varying morphology may play an important role in cancer progression.

Exosome Transfer Between Different Co-implanted Human Pancreatic Cancer Cell Lines Occurs in the Primary Tumor and Multiple Metastatic Sites of Nude Mice But Not in Co-Culture In Vitro.

BACKGROUND/AIM: Exosome exchange between cancer cells or between cancer and stromal cells is involved in cancer metastasis. We have previously developed in vivo color-coded labeling of cancer cells and stromal cells with spectrally-distinct fluorescent genetic reporters to demonstrate the role of exosomes in metastasis. In the present study, we studied exosome transfer between different pancreatic-cancer cell lines in vivo and in vitro and its potential role in metastasis. MATERIALS AND METHODS: Human pancreatic-cancer cell lines AsPC-1 and MiaPaCa-2 were used in the present study. AsPC-1 cells contain a genetic exosome reporter gene labeled with green fluorescent protein (pCT-CD63-GFP) and MiaPaCa-2 cells express red fluorescent protein (RFP). Both cell lines were co-injected into the spleen of nude mice (n=5) to further study the role of exosome exchange in metastasis. Three weeks later mice were sacrificed and tumors at the primary and metastatic sites were cultured and observed by confocal fluorescence microscopy for exosome transfer. RESULTS: The primary tumor formed in the spleen and metastasized to the liver, as observed macroscopically. Cells were cultured from the spleen, liver, lung, bone marrow and ascites. Transfer of exosomes from AsPC-1 to MiaPaCa-2 was demonstrated in the cultured cells by confocal fluorescence microscopy. Moreover, cell fusion was also observed along with exosome transfer. Exosome transfer did not occur during in vitro co-culture between the two pancreatic-cancer cell lines, suggesting a role of the tumor microenvironment (TME) in exosome transfer. CONCLUSION: The transfer of exosomes between different pancreatic-cancer cell lines was observed during primary-tumor and metastatic growth in nude mice. This cell-cell communication might be a trigger of cell fusion and promotion of cancer metastasis. Exosome transfer between the two pancreatic-cancer cell lines appears to be facilitated by the TME, as it did not occur during in vitro co-culture.

Benefits of linked color imaging for recognition of early differentiated-type gastric cancer: in comparison with indigo carmine contrast method and blue laser imaging.

BACKGROUND AND AIM: Linked color imaging (LCI) is a novel endoscopy system, which enhances slight differences in mucosal color. However, whether LCI is more useful than other kinds of image-enhanced endoscopy (IEE) in recognizing early gastric cancer remains unclear. This study aimed to evaluate LCI efficacy compared with the indigo carmine contrast method (IC), and blue laser imaging-bright (BLI-brt) in early differentiated-type gastric cancer recognition. METHODS: We retrospectively analyzed early differentiated-type gastric cancer, which were examined by all four imaging techniques (white light imaging, IC, LCI, BLI-brt) at Asahi University Hospital from June 2014 to November 2018. Both subjective evaluation (using ranking score: RS) and objective evaluation (using color difference score: CDS) were adopted to quantify early differentiated-type gastric cancer recognition. RESULTS: During this period, 87 lesions were enrolled in this study. Both RS and CDS of LCI were significantly higher (p < 0.01) than those of IC and BLI-brt. Both RS and CDS of BLI-brt had no significant difference compared with those of IC. Subgroup analysis revealed that LCI was especially useful in post-Helicobacter pylori eradication patients and flat or depressed lesions compared with IC and BLI-brt. CONCLUSIONS: LCI appears to be more beneficial for the recognition of early differentiated-type gastric cancer in endoscopic screenings than IC and BLI-brt from the middle to distant view.

Recurrence of Cutaneous and Lymph Node Metastases 12 Years after Radical Total Gastrectomy for Stage IIA Gastric Cancer.

We herein report a rare case of cutaneous and lymph node metastases that recurred 12 years after radical total gastrectomy for stage IIA gastric cancer. A 62-year-old man had undergone total gastrectomy for stage IIA gastric cancer 12 years earlier without postoperative adjuvant chemotherapy. At 12 years after the surgery, he was admitted for left jugular swelling. Computed tomography revealed supraclavicular lymph node swelling and precordial subcutaneous edema. The lymph node specimens and cutaneous biopsies indicated late recurrence of the gastric cancer. Concurrent chemoradiotherapy was administered effectively, but after eight months, the patient died due to deterioration in his general condition.

Successful treatment of unresectable advanced rectal cancer with liver metastases by hemostasis re-irradiation of the rectal cancer and palliative low-dose whole-liver radiation therapy: a case report.

A 72-year-old man was admitted to the hospital with fatigue. Colonoscopy revealed a 50 × 50 mm rectal tumor with bleeding. Based on close inspection, he was diagnosed with unresectable advanced rectal cancer with multiple liver metastases. Chemotherapy was administered as 10 cycles of bevacizumab + mFOLFOX6 and 7 cycles of bevacizumab + FOLFIRI. Nine months later, he presented with hematochezia and progression of anemia. It was difficult to stop the bleeding via endoscopy. He underwent radiation therapy (39 Gy in 13 fractions), and hemostasis was confirmed. Then, further chemotherapy was performed with 3 cycles of bevacizumab + FOLFIRI and 2 cycles of TAS102. However 14 months after the initial visit, he presented with right hypochondralgia and abdominal fullness due to the progression of multiple liver metastases. Palliative low-dose whole-liver radiation therapy (WLRT) (30 Gy in 10 fractions) was performed. He developed Grade 2 nausea, but his right hypochondralgia reduced, liver dysfunction improved, and he successfully completed radiotherapy. At approximately the same time his anemia progressed, and colonoscopy revealed recurrent bleeding from the tumor. Re-irradiation (15 Gy in 5 fractions) of the rectal tumor was carried out and a blood transfusion was performed for the bleeding. He was discharged after confirmation the anemia had not progressed. Few reports have been published on the use of both palliative re-irradiation to stop bleeding from rectal cancer and palliative low-dose WLRT. Based on our experience with this case, we believe that palliative radiotherapy can be useful in treating patients with a poor prognosis.

Potential of automatic diagnosis system with linked color imaging for diagnosis of Helicobacter pylori infection.

BACKGROUND AND AIM: It is necessary to establish universal methods for endoscopic diagnosis of Helicobacter pylori (HP) infection, such as computer-aided diagnosis. In the present study, we propose a multistage diagnosis algorithm for HP infection. METHODS: The aims of this study are to: (i) to construct an interpretable automatic diagnostic system using a support vector machine for HP infection; and (ii) to compare the diagnosis capability of our artificial intelligence (AI) system with that of endoscopists. Presence of an HP infection determined through linked color imaging (LCI) was learned through machine learning. Trained classifiers automatically diagnosed HP-positive and -negative patients examined using LCI. We retrospectively analyzed the new images from 105 consecutive patients; 42 were HP positive, 46 were post-eradication, and 17 were uninfected. Five endoscopic images per case taken from different areas were read into the AI system, and used in the HP diagnosis. RESULTS: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the diagnosis of HP infection using the AI system were 87.6%, 90.4%, 85.7%, 80.9%, and 93.1%, respectively. Accuracy of the AI system was higher than that of an inexperienced doctor, but there was no significant difference between the diagnosis of experienced physicians and the AI system. CONCLUSIONS: The AI system can diagnose an HP infection with significant accuracy. There remains room for improvement, particularly for the diagnosis of post-eradication patients. By learning more images and considering a diagnosis algorithm for post-eradication patients, our new AI system will provide diagnostic support, particularly to inexperienced physicians.

Hypothyroidism Enhanced Portal Hypertension in a Patient with Alcoholic Liver Cirrhosis, Resulting in the Development of Ascites.

A man diagnosed with alcoholic liver cirrhosis complained of abdominal distention due to massive ascites. The ascites did not resolve with diuretic agents. The serum-ascites albumin gradient value of 1.9 g/dL and the total protein level in the ascites of 3.1 g/dL indicated the ascites to have been caused by portal hypertension. Hypothyroidism was detected, and the patient received supplementation with levothyroxine. The ascites dramatically decreased after supplementation with levothyroxine. We herein conclude that the ascites in the present case had thus been strongly influenced by portal hypertension, which was induced by liver dysfunction associated with liver cirrhosis and hypothyroidism.