Exosomal microRNAs derived from colon cancer cells promote tumor progression by suppressing fibroblast TP53 expression.

The tumor microenvironment offers favorable conditions for tumor progression, and activated fibroblasts, known as cancer-associated fibroblasts, play a pivotal role. TP53-deficient cancer cells are known to induce strong fibroblast activation. We aimed to elucidate the oncogenic role of exosomes derived from TP53-deficient colon cancer cells in fibroblast proliferation and tumor growth. Cancer cell-derived exosomes (CDEs) were isolated from the conditioned media of cancer cells using a sequential ultracentrifugation method. The effects of exosomes on tumor growth were evaluated using human cell lines (TP53-WT colon cancer, HCT116; TP53-mutant colon cancer, HT29; and fibroblasts, CCD-18Co and WI-38) and an immune-deficient nude mouse xenograft model. HCT116 (HCT116sh p53 ) cells deficient in TP53 accelerated cocultured fibroblast proliferation compared to TP53-WT HCT116 (HCT116sh control ) cells in vitro. Exosomes from HCT116sh p53 cells suppressed TP53 expression of fibroblasts and promoted their proliferation. Xenografts of HCT116sh p53 cells grew significantly faster than those of HCT116sh control cells in the presence of co-injected fibroblasts, but this difference was diminished by CDE inhibition. Microarray analysis identified upregulation of several microRNAs (miR-1249-5p, miR-6737-5p, and miR-6819-5p) in TP53-deficient CDEs, which were functionally proven to suppress TP53 expression in fibroblasts. Exosomes derived from TP53-mutant HT29 cells also suppressed TP53 expression in fibroblasts and accelerated their growth. The proliferative effect of HT29 on cocultured fibroblasts was diminished by inhibition of these miRNAs in fibroblasts. Our results suggest that CDEs play a pivotal role in tumor progression by fibroblast modification. Cancer cell-derived exosomes might, therefore, represent a novel therapeutic target in colon cancer.

The heart's exposure to radiation increases the risk of cardiac toxicity after chemoradiotherapy for superficial esophageal cancer: a retrospective cohort study.

BACKGROUND: Chemoradiotherapy effectively treats superficial esophageal cancer and is optimal to preserve organs. However, late toxicity, particularly in cardiac diseases, obstructs clinical outcomes. We revealed the risk factors for cardiac event development post-chemoradiotherapy. METHODS: Data from 80 patients who were diagnosed with submucosal invasive esophageal cancer without metastasis (confirmed using multiple modalities) and who underwent chemoradiotherapy between 2006 and 2014 were analyzed. Patients were 11% (9/80) female, and the median age and follow-up were 66.5 y and 73 mo, respectively. We calculated the individual radiation dose to the heart and analyzed relationships between the cardiac event occurrence rate and each clinical factor. RESULTS: The 5-y overall and recurrence-free survival rates were 74.6 and 62.4%, respectively. Among the total number of deaths, 34.6% was caused by esophageal cancer. During the follow-up, 13 patients developed severe cardiac events (ischemic heart diseases, n = 7; pericardial effusion, n = 3, atrial fibrillation, n = 1; and sudden death, n = 2). The significant risk factor for cardiac events post-chemoradiotherapy was the level of the heart's exposure to radiation, with higher exposure associated with greater occurrence. History of smoking, obesity, comorbidity, and history of cardiac disease were unrelated to cardiac event occurrence post-chemoradiotherapy. CONCLUSIONS: Chemoradiotherapy is a favorable intervention for superficial esophageal cancer. Reducing the radiation dose to the heart likely contributes to preventing cardiac toxicity post-chemoradiotherapy.

Adenoma of colorectal laterally spreading tumor nongranular type with biological phenotypic features similar to cancer.

BACKGROUND AND AIM: Colorectal laterally spreading tumors (LSTs) are morphologically subdivided into granular (LST-G) and nongranular (LST-NG) categories. We aimed to elucidate the differences in oncogenic characteristics between the two types. METHODS: Laterally spreading tumors resected by endoscopic submucosal dissection and surgery from March 2009 to May 2017 were examined for p53 positivity, Ki-67 labeling index (LI), microvessel density, degree of fibrosis, intensities of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), and expression of acid mucins. We compared these factors between adenomas, noninvasive cancers, and invasive cancers, both LST-G and LST-NG. RESULTS: Ninety-three LST-G (53 adenomas [LST-GA] and 40 cancers [LST-GC]) and 55 LST-NG (24 adenomas [LST-NGA] and 31 cancers [LST-NGC]) were evaluated. Although p53 positivity was lower in LST-GA than in LST-NGA (P < 0.001), there was no difference between LST-GC and LST-NGC. Ki-67 LI was higher in LST-NGA than in LST-GA (P < 0.001) and higher in LST-NGC than in LST-GC of noninvasive cancers (P < 0.001). Microvessel density and degree of fibrosis were higher in LST-NGA than in LST-GA (P < 0.001), and intensities of iNOS and NT were also higher in LST-NGA than in LST-GA (P < 0.001). Expression of acid mucins was lower in LST-NGA than in LST-GA (P < 0.001). Although there were significant differences in p53 positivity, Ki-67 LI, microvessel density, degree of fibrosis, intensities of iNOS and NT, and expression of acid mucins between LST-GA and LST-NGA, these factors were only slightly different between LST-GC and LST-NGC of invasive cancers. CONCLUSIONS: Unlike LST-GA, LST-NGA possessed phenotypic features similar to cancer.

Cardiac metastasis from colon cancer effectively treated with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab: a case report.

BACKGROUND: Cardiac metastasis from colorectal cancer is rare. There is little evidence supporting the effectiveness of chemotherapy, and standard therapy for metastatic cardiac tumors has not been established. CASE PRESENTATION: A 76-year-old woman presented with a right ventricle tumor that was detected incidentally on screening cardiac ultrasonography. The initial computed tomography (CT) scan showed the cardiac tumor, which was approximately 40 mm in size, and multiple pulmonary nodules. Serum levels of tumor markers CEA and CA19-9 were elevated aberrantly. The suspected primary tumor, a well-differentiated adenocarcinoma of the transverse colon with wild-type KRAS was found by colonoscopy, and treatment with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab was initiated. After 4 courses of the therapy, a CT scan showed that the cardiac tumor size had markedly decreased and the pulmonary nodules had diminished. The serum levels of CEA and CA19-9 were also markedly decreased. After 12 courses of chemotherapy during 10 months of treatment, the patient continued to show a partial response, and she remained asymptomatic with continuation of the treatment through 15 courses. CONCLUSION: To the best of our knowledge, this is the first report of the efficacy of combination therapy using cytotoxic and molecular targeted agents against cardiac metastasis from colon cancer.

Integrated diagnostic strategy for the invasion depth of early gastric cancer by conventional endoscopy and EUS.

BACKGROUND: Although conventional endoscopy (CE) and EUS are considered useful for predicting the invasion depth (T-staging) in early gastric cancer (EGC), no effective diagnostic strategy has been established. OBJECTIVE: To produce simple CE criteria and to elucidate an efficient diagnostic method by combining CE and EUS for accurate T-staging. DESIGN: Single-center retrospective analysis. SETTING: Academic university hospital. PATIENTS: Consecutive patients with EGC from April 2007 to March 2012 who underwent CE and EUS before treatment. INTERVENTIONS: Recorded endoscopic images were independently reviewed by 3 observers. The CE criteria for massive invasion were defined, and their utility and the additional value of EUS were assessed. MAIN OUTCOME MEASUREMENTS: The accuracy of CE based on the criteria and the accuracy of EUS. RESULTS: Two hundred thirty patients were enrolled: 195 with mucosal cancer or cancer in the submucosa less than 500 µm from the muscularis mucosae and 35 with invasive cancers. Multivariate analysis of the CE findings by 1 observer revealed that an irregular surface and a submucosal tumor-like marginal elevation were significantly associated with massive invasion. The simple CE criteria, consisting of those 2 features, had an overall accuracy of 73% to 82% and no significant differences in the diagnostic yield compared with EUS in all observers. CE accurately revealed mucosal cancer, and EUS efficiently salvaged the lesions that were over-diagnosed by CE. With our strategy, which involved the CE criteria and the optimal use of EUS, the comprehensive accuracy exceeded 85% in each observer. LIMITATIONS: Retrospective, single-center study. CONCLUSIONS: We demonstrated a practical strategy for T-staging in EGC using simple CE criteria and EUS.

The effectiveness of an anti-human IL-6 receptor monoclonal antibody combined with chemotherapy to target colon cancer stem-like cells.

Recent studies have demonstrated that cancer stem cells (CSCs) can initiate and sustain tumor growth and exhibit resistance to clinical cytotoxic therapies. Therefore, CSCs represent the main target of anticancer therapy. Interleukin-6 (IL-6) promotes cellular proliferation and drug resistance in colorectal cancer, and its serum levels correlate with patient survival. Therefore, IL-6 and its downstream signaling molecule the signal transducer and activator of transcription-3 (STAT3) represent potential molecular targets. In the present study, we investigated the effects of IL-6 and its downstream signaling components on stem cell biology, particularly the chemoresistance of CSCs, to explore potential molecular targets for cancer therapy. The colon cancer cell line WiDr was cultured in serum-free, non-adherent, and three-dimensional spheroid-forming conditions to enrich the stem cell-like population. Spheroid-forming cells slowly proliferated and expressed high levels of Oct-4, Klf4, Bmi-1, Lgr5, IL-6, and Notch 3 compared with adherent cells. Treatment with an anti-human IL-6 receptor monoclonal antibody reduced spheroid formation, stem cell-related gene expression, and 5-fluorouracil (5-FU) resistance. In addition, IL-6 treatment enhanced the levels of p-STAT3 (Tyr705), the expression of Oct-4, Klf4, Lgr5, and Notch 3, and chemoresistance to 5-FU. siRNA targeting Notch 3 suppressed spheroid formation, Oct-4 and Lgr5 expression, and 5-FU chemoresistance, whereas STAT3 inhibition enhanced Oct-4, Klf4, Lgr5, and Notch 3 expression and 5-FU chemoresistance along with reduced spheroid growth. Taken together, these results indicate that IL-6 functions in dichotomous pathways involving Notch 3 induction and STAT3 activation. The former pathway is involved in cancer stem-like cell biology and enhanced chemoresistance, and the latter pathway leads to accelerated proliferation and reduced chemoresistance. Thus, an anti-human IL-6 receptor monoclonal antibody or Notch 3 inhibition may be superior to STAT3 inhibition for CSC-targeting therapies concomitant with anticancer drugs.

Esophageal adenocarcinoma with white opaque substance observed by magnifying endoscopy with narrow band imaging.

White opaque substance (WOS) is observed in the gastric neoplasia of 0-IIa type using magnifying endoscopy with narrow band imaging (NBI-ME). Colonic and duodenal neoplasms with WOS have also been reported. Immunohistochemical examination with adipophilin reveals WOS in gastric neoplasms as lipid droplets, and WOS is specific for neoplasm with intestinal or gastrointestinal phenotype. We herein report a case of adenocarcinoma of the esophagogastric junction with WOS. A male patient in his sixties was found by esophagogastroduodenoscopy to have an esophageal elevated lesion. NBI-ME showed whitish deposits that looked similar to WOS in gastric neoplasms. The patient underwent endoscopic submucosal dissection and the lesion was resected in a single piece. This tumor had diffuse positivity for adipophilin and gastrointestinal phenotype.

5­FU resistance abrogates the amplified cytotoxic effects induced by inhibiting checkpoint kinase 1 in p53­mutated colon cancer cells.

The emergence of chemoresistance is a major limitation of current cancer therapies, and checkpoint kinase (Chk1) 1 positively correlates with resistance to chemo­ or radio­therapy. Cancer cells lacking p53 pathways are completely dependent on the S and G2/M checkpoints via Chk1; therefore, Chk1 inhibition enhances the cytotoxicity of DNA­damaging agents only in p53­deficient cells. However, little is known about the synergistic effect of Chk1 inhibition with 5­FU, the most frequently used antimetabolite, in chemoresistant colorectal cells. In this study, we found that 5­FU induced S­phase arrest only in p53­deficient colorectal cancer cells. 5­FU treatment induced DNA damage and activation of ataxia telangiectasia mutated (ATM) and Chk1, leading to S­phase arrest, and Chk1 inhibition using SB218078 reduced S­phase arrest and increased apoptosis in the presence of 5­FU. In contrast, in p53­deficient, 5­FU­resistant (5FUR) colon cancer cells that we developed, 5­FU enhanced DNA damage but did not induce Chk1/ATM activation or cell cycle arrest. SB218078 in combination with 5­FU did not induce apoptosis. These results indicate that 5­FU­resistance abrogated the anticancer effect amplified by Chk1 inhibition, even in p53­deficient cancer cells.

[Concomitant use of romiplostim and chemotherapy for advanced rectal cancer associated with idiopathic thrombocytopenic purpura].

A woman in her 60s was referred to our department with advanced rectal cancer and multiple unresectable metastases of the liver and peritoneum. She had been diagnosed with idiopathic thrombocytopenic purpura (ITP) in her 20s, with a platelet count maintained at approximately 1.0×10(4)/µL by prednisolone; on admission, her platelet count was 0.9×10(4)/µL. Romiplostim, a thrombopoietin receptor agonist, was administered prior to chemotherapy. Her platelet count increased to approximately 10.0×10(4)/µL during chemotherapy with oxaliplatin plus capecitabine, and she developed deep venous thrombosis requiring inferior vena cava filter placement and anticoagulation. No other severe adverse events occurred. There is no standard regimen for the treatment of solid tumors in patients with ITP. This is the first reported case of the concomitant use of romiplostim and chemotherapy for advanced rectal cancer. We believe that romiplostim can effectively salvage the platelet count in emergency situations such as during chemotherapy.

[A case of granulocyte colony-stimulating factor-producing adenosquamous carcinoma of the liver accompanied by an adenocarcinoma of the ascending colon and urothelial carcinoma of the urinary bladder].

An 83-year-old man was admitted with renal dysfunction, anemia, and peripheral leukocytosis. His peripheral leukocyte count was 41000/µl. A computed tomography scan revealed a solid cystic mass in the liver, mural thickening in the ascending colon and nodules in the right lower lung field. Colonoscopy revealed ascending colon cancer, and analysis of the biopsy specimens revealed well-differentiated adenocarcinoma. However, although a liver abscess was suspected, pus and bacteria were not found in the cystic lesion of the liver mass, the solid lesion of the mass was diagnosed as carcinoma. The serum concentration of granulocyte colony-stimulating factor (G-CSF) was elevated to 256 pg/ml. Because his general condition worsened, we could not treat these tumors, but he died 38 days after admission. Autopsy revealed adenosquamous carcinoma of the liver, well-differentiated adenocarcinoma of the ascending colon, urothelial carcinoma of the urinary bladder, and metastatic squamous cell carcinoma of the lung. Immunohistochemical analysis revealed positive staining for G-CSF in the liver tumor sample.