EGFR and Prion protein promote signaling via FOXO3a-KLF5 resulting in clinical resistance to platinum agents in colorectal cancer

Epidermal growth factor receptor (EGFR) supports colorectal cancer progression via oncogenic signaling. Anti-EGFR therapy is being investigated as a clinical option for colorectal cancer, and an observed interaction between EGFR and Prion protein has been detected in neuronal cells. We hypothesized that PrPC expression levels may regulate EGFR signaling and that detailed understanding of this signaling pathway may enable identification of resistance mechanisms and new actionable targets in colorectal cancer. We performed molecular pathway analysis following knockdown of PrPC or inhibition of EGFR signaling via gefitinib to identify changes in expression of key signaling proteins that determine cellular sensitivity or resistance to cisplatin. Expression of these proteins was examined in matched primary and metastatic patient samples and was correlated for resistance to therapy and progression of disease. Utilizing three colorectal cancer cell lines, we observed a correlation between high expression of PrPC and resistance to cisplatin. Investigation of molecular signaling in a resistant cell line revealed that PrPC contributed to signaling via colocalization with EGFR, which could be overcome by targeting p38 mitogen-activated protein kinases (p38 MAPK). We revealed that the level of Krüppel-like factor 5 (KLF5), a target downstream of p38 MAPK, was predictive for cell line and patient response to platinum agents. Further, high KLF5 expression was observed in BRAF-mutant colorectal cancer. Our study indicates that the EGFR to KLF5 pathway is predictive of patient progression on platinum-based therapy

Oncogenic BRAF mutation induces DNA methylation changes in a murine model for human serrated colorectal neoplasia

Colorectal cancer is a major cause of cancer death and approximately 20% arises within serrated polyps, which are under-recognized and poorly understood. Human serrated colorectal polyps frequently exhibit both oncogenic BRAF mutation and widespread DNA methylation changes, which are important in silencing genes restraining neoplastic progression. Here, we investigated whether in vivo induction of mutant Braf is sufficient to result in coordinated promoter methylation changes for multiple cancer-related genes. The BrafV637E mutation was induced in murine intestine on an FVB;C57BL/6J background and assessed for morphological and DNA methylation changes at multiple time points from 10 days to 14 months. Extensive intestinal hyperplasia developed by 10 days post-induction of the mutation. By 8 months, most mice had murine serrated adenomas with dysplasia and invasive cancer developed in 40% of mice by 14 months. From 5 months onwards, Braf mutant mice showed extensive, gene-specific increases in DNA methylation even in hyperplastic mucosa without lesions. This demonstrates that persistent oncogenic Braf signaling is sufficient to induce widespread DNA methylation changes. This occurs over an extended period of time, mimicking the long latency followed by rapid progression of human serrated neoplasia. This study establishes for the first time that DNA methylation arises slowly in direct response to prolonged oncogenic Braf signaling in serrated polyps; this finding has implications both for chemoprevention and for understanding the origin of DNA hypermethylation in cancer generally.Catherine E. Bond, Cheng Liu, Futoshi Kawamata, Diane M. McKeone, Winnie Fernando, Saara Jamieson, Sally-Ann Pearson, Alexandra Kane, Susan L. Woods, Tamsin R.M. Lannagan, Roshini Somashekar, Young Lee, Troy Dumenil, Gunter Hartel, Kevin J. Spring, Jennifer Borowsky, Lochlan Fennell, Mark Bettington, Jason Lee, Daniel L. Worthley, Barbara A. Leggett and Vicki L.J. Whitehal

Copy number profiles of paired primary and metastatic colorectal cancers

This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Liver metastasis is the major cause of death following a diagnosis of colorectal cancer (CRC). In this study, we compared the copy number profiles of paired primary and liver metastatic CRC to better understand how the genomic structure of primary CRC differs from the metastasis. Paired primary and metastatic tumors from 16 patients and their adjacent normal tissue samples were analyzed using single nucleotide polymorphism arrays. Genome-wide chromosomal copy number alterations were assessed, with particular attention to 188 genes known to be somatically altered in CRC and 24 genes that are clinically actionable in CRC. These data were analyzed with respect to the timing of primary and metastatic tissue resection and with exposure to chemotherapy. The genomic differences between the tumor and paired metastases revealed an average copy number discordance of 22.0%. The pairs of tumor samples collected prior to treatment revealed significantly higher copy number differences compared to post-therapy liver metastases (P = 0.014). Loss of heterozygosity acquired in liver metastases was significantly higher in previously treated liver metastasis samples compared to treatment naive liver metastasis samples (P = 0.003). Amplification of the clinically actionable genes ERBB2, FGFR1, PIK3CA or CDK8 was observed in the metastatic tissue of 4 patients but not in the paired primary CRC. These examples highlight the intra-patient genomic discrepancies that can occur between metastases and the primary tumors from which they arose. We propose that precision medicine strategies may therefore identify different actionable targets in metastatic tissue, compared to primary tumors, due to substantial genomic differences

Reduced port surgery for UC

Introduction: Reduced-port laparoscopic surgery is a novel minimally invasive surgery. However, reduced-port surgery for ulcerative colitis (UC) remains controversial. Here, we describe the clinical outcomes of single-incision plus one port laparoscopic surgery (SILS + 1) for medically uncontrolled UC. Methods: Between May 2011 and September 2014, 10 UC patients underwent SILS + 1 port surgery. All procedures were performed with the use of a SILS port and either a 5-mm or a 12-mm port placed at the planned ileostomy site. Results: The median age of patients was 32 years (range, 22-53 years). Six patients underwent two-stage SILS + 1 port restorative proctocolectomy with ileal pouch-anal anastomosis, two patients underwent SILS + 1 total proctocolectomy, and the remaining two patients underwent SILS + 1 subtotal colectomy with subsequent three-stage SILS + 1 ileal pouch-anal anastomosis. The median operative time was 363.1 min (range, 253-465 min) and the median estimated blood loss was 29 mL (range, 0-100 mL). There were no conversions or additional ports required. Two patients previously underwent SILS + 1 subtotal colectomy, and in one of those patients, SILS + 1 ileal pouch-anal anastomosis was performed successfully 6 months after the previous surgery. There were no intra-abdominal adhesions, and no extra wounds were necessary because the previous stoma site had been used to access the SILS port. The median postoperative period was 24 months, during which five patients had their ileostomies closed. No patients reported occasional minor daily soiling or the need to wear a pad. Conclusion: Reduced-port laparoscopic surgery for medically uncontrolled UC is a feasible and safe procedure when performed by skilled surgeons

Comparison of Single-Incision Plus One Additional Port Laparoscopy-assisted Anterior Resection with Conventional Laparoscopy-assisted Anterior Resection for Rectal Cancer

Reduced-port laparoscopic surgery is the latest innovation in minimally invasive surgery. We performed single-incision plus one additional port laparoscopy-assisted anterior resection (SILS + 1-AR) starting in August 2010. This study aimed at evaluating the feasibility of SILS + 1-AR and comparing it with that of conventional laparoscopy-assisted anterior resection (C-AR). Patients with preoperative clinical stage 0 to stage III rectal cancer were included. Demographic, intraoperative, and pathological examination data, as well as short-term outcome data, of 20 patients who underwent SILS + 1-AR were retrospectively compared with that of 20 patients who underwent C-AR. Invasiveness of the two procedures was also evaluated through a vital signs diary and hematological examination on postoperative days (POD) 1, 3, and 7. Operating time, mean estimated blood loss, the number of lymph nodes dissected, the number of lymph node metastases, and the mean distal resection margin length were not significantly different. However, postoperative neutrophil counts in the SILS + 1-AR group were lower than those in the C-AR group (P = 0.085). A significant difference in body temperature was observed in the SILS + 1-AR group on POD 1 (P = 0.028). No significant differences were observed in perioperative and overall morbidity between the two groups. Conversion to open surgery was required in 2 (10 %) of the 20 patients in the SILS + 1-AR group. The mean postoperative length of stay and recurrence rates were similar in the two groups. SILS + 1-AR for rectal cancer is similar to C-AR in safety, feasibility, and provision of oncological radicality

Intraoperative localization of arteriovenous malformation of a jejunum with combined use of angiographic methods and indocyanine green injection : Report of a new technique

INTRODUCTION: The localization of small intestine sources of obscure gastrointestinal bleeding has been a challenge. The use of indocyanine green (ICG) is effective in aiding intraoperative localization if a bleeding lesion is identified on angiography. CASE PRESENTATION: A 95-year-old Japanese man presented with hematochezia. Selective angiography of the superior mesenteric artery (SMA) established an arteriovenous malformation (AVM). ICG injection into the feeding vessel was administered intraoperatively, and the demarcated segment of the jejunum was resected. DISCUSSION: Diluted ICG was injected in the SMA by intraoperative angiography, and the region could be easily and clearly visualized by the ICG fluorescence imaging; small patchy poolings of ICG were recognized. Ultimately, the region was diagnosed as an AVM of the jejunum. To the best of our knowledge, this is the first reported description of this technique. CONCLUSION: Our new technique of combining selective angiography with intraoperative ICG injection and focused enterectomy is a safe, accurate, and cost-effective treatment

Intracellular localization of mesothelin predicts patient prognosis of extrahepatic bile duct cancer.

Mesothelin is expressed in various types of malignant tumors, and we recently reported that the expression of mesothelin was related to unfavorable patient outcome in pancreatic ductal adenocarcinoma and gastric adenocarcinoma. In this study, we examined the clinicopathological significance of mesothelin expression in extrahepatic bile duct cancer (EHBDCA), especially in terms of its association with the staining pattern. Tissue samples from 61 EHBDCA (16 hilar cholangiocarcinoma, 17 upper bile duct adenocarci-noma, 20 middle bile duct adenocarcinoma and 8 distal bile duct adenocarcinoma) were immunohistochemically examined. The expression levels of mesothelin in tumor cells was classified into the localization of mesothelin in luminal membrane and/or cytoplasm, in addition to high and low according to the staining intensity and proportion as a conventional analysis. 'High-level expression' of mesothelin (47.5%) was statistically correlated with liver metastasis (P=0.013) and poorer patient outcome (P=0.022), while 'luminal membrane positive' of mesothelin (52.5%) was more significantly correlated with liver metastasis (P=0.006), peritoneal metastasis (P=0.024) and unfavorable patient outcome (P=0.017). Moreover, we found that 'cytoplasmic expression' isolated from 'luminal membrane negative' of mesothelin represented the best patient prognosis throughout this study. We describe the expression pattern level of mesothelin, i.e., in luminal membrane or cytoplasm both high and low level, evidently indicate the patient prognosis of EHBDCA, suggesting the pivotal role of mesothelin in cancer promotion depending on its intracellular localization