Epithelial-specific ERBB3 deletion results in a genetic background-dependent increase in intestinal and colon polyps that is mediated by EGFR

ERBB3 has gained attention as a potential therapeutic target to treat colorectal and other types of cancers. To confirm a previous study showing intestinal polyps are dependent upon ERBB3, we generated an intestinal epithelia-specific ERBB3 deletion in C57BL/6-ApcMin/+ mice. Contrary to the previous report showing a significant reduction in intestinal polyps with ablation of ERBB3 on a B6;129 mixed genetic background, we observed a significant increase in polyp number with ablation of ERBB3 on C57BL/6J compared to control littermates. We confirmed the genetic background dependency of ERBB3 by also analyzing polyp development on B6129 hybrid and B6;129 advanced intercross mixed genetic backgrounds, which showed that ERBB3 deficiency only reduced polyp number on the mixed background as previously reported. Increased polyp number with ablation of ERBB3 was also observed in C57BL/6J mice treated with azoxymethane showing the effect is model independent. Polyps forming in absence of ERBB3 were generally smaller than those forming in control mice, albeit the effect was greatest in genetic backgrounds with reduced polyp numbers. The mechanism for differential polyp number in the absence of ERBB3 was through altered proliferation. Backgrounds with increased polyp number with loss of ERBB3 showed an increase in cell proliferation even in non-tumor epithelia, while backgrounds showing reduced polyp number with loss of ERBB3 showed reduced cellular proliferation. Increase polyp number caused by loss of ERBB3 was mediated by increased epidermal growth factor receptor (EGFR) expression, which was confirmed by deletion of Egfr. Taken together, this study raises substantial implications on the use of ERBB3 inhibitors against colorectal cancer. The prediction is that some patients may have increased progression with ERBB3 inhibitor therapy, which is consistent with observations reported for ERBB3 inhibitor clinical trials.

Danish guidelines for management of non-APC-associated hereditary polyposis syndromes

Hereditary Polyposis Syndromes are a group of rare, inherited syndromes characterized by the presence of histopathologically specific or numerous intestinal polyps and an increased risk of cancer. Some polyposis syndromes have been known for decades, but the development in genetic technologies has allowed the identification of new syndromes.. The diagnosis entails surveillance from an early age, but universal guideline on how to manage and surveille these new syndromes are lacking. This paper represents a condensed version of the recent guideline (2020) from a working group appointed by the Danish Society of Medical Genetics and the Danish Society of Surgery on recommendations for the surveillance of patients with hereditary polyposis syndromes, including rare polyposis syndromes.

Endoscopic and Histopathological Characteristics of Polypoid and Non-Polypoid Colorectal Lesions in Patients of a Social Security Hospital of Lambayeque, Peru

Objective: To describe the endoscopic and histopathological characteristics of polypoid and non-polypoid colorectal lesions at the Luis Heysen Inchaustegui hospital, Peru, 2017-2018. Materials and methods: Descriptive-analytical cross-sectional study. We study epidemiological, endoscopic and histopathological variables. location, Size and shape of the lesions taking into account the Paris classification. Results: Endoscopically, of a total of 81 colorectal lesions, the majority were non-polypoid (71.6%). Lesions smaller than 10mm represented 90.1% in non-polypoid lesions and 56.5 % in polypoid lesions. Histopathologically, non-adenomatous lesions predominated (53.0%). Conclusions: The most frequent lesions were non-polypoid, the main location being the rectum; while in polypoid lesions, the transverse colon. Regarding size, lesions smaller than 10mm predominated in both non-polypoid and polypoid lesions. Histopathologically, the most frequent were non-adenomatous lesions (hyperplastic polyps); for its part, the predominant adenoma subtype was tubular. Keywords: Adenomas; Polyps; Intestinal Polyps; Colon (source: DeCS BIREME).

Intestinal schistosomiasis masquerading as intestinal polyps

Background Schistosomiasis is very common in the southern part of the Yangtze River Basin in China. It is mainly manifested as appendicitis, ulcers, hematomas, and thickening of the intestinal tract. Schistosomiasis of the appendix is rare, mainly manifested as appendicitis, which is easy to be misdiagnosed. Case presentation Here we report a rare case of a Chinese female whose intestinal mass manifested as intestinal polyps and was eventually diagnosed pathologically as schistosomiasis infection (appendix schistosomiasis). So far, there are rare relevant cases reported. Conclusions Intestinal schistosomiasis is easily misdiagnosed, and appendix schistosomiasis is rare. The final diagnosis requires pathology, especially surgical pathology.

Cdx2 Regulates Intestinal EphrinB1 through the Notch Pathway

The majority of colorectal cancers harbor loss-of-function mutations in APC, a negative regulator of canonical Wnt signaling, leading to intestinal polyps that are predisposed to malignant progression. Comparable murine APC alleles also evoke intestinal polyps, which are typically confined to the small intestine and proximal colon, but do not progress to carcinoma in the absence of additional mutations. The Cdx transcription factors Cdx1 and Cdx2 are essential for homeostasis of the intestinal epithelium, and loss of Cdx2 has been associated with more aggressive subtypes of colorectal cancer in the human population. Consistent with this, concomitant loss of Cdx1 and Cdx2 in a murine APC mutant background leads to an increase in polyps throughout the intestinal tract. These polyps also exhibit a villous phenotype associated with the loss of EphrinB1. However, the basis for these outcomes is poorly understood. To further explore this, we modeled Cdx2 loss in SW480 colorectal cancer cells. We found that Cdx2 impacted Notch signaling in SW480 cells, and that EphrinB1 is a Notch target gene. As EphrinB1 loss also leads to a villus tumor phenotype, these findings evoke a mechanism by which Cdx2 impacts colorectal cancer via Notch-dependent EphrinB1 signaling.

Laparoscopic-assisted disinvagination and polypectomy for multiple intussusceptions induced by small intestinal polyps in patients with Peutz-Jeghers syndrome: a case report

Background Peutz–Jeghers syndrome (PJS) is a very rare autosomal dominant genetic disorder characterized by hamartomatous polyps in the gastrointestinal tract and hyperpigmentation of the lips, hands, and feet. The hamartomatous polyps in the small intestine often cause intussusception and bleeding. Case presentation A 62-year-old male was hospitalized for treatment of deep vein thrombosis and pulmonary embolism. In the small intestine, computed tomography showed three small polyps with intussusceptions. Since the patient had gastrointestinal polyposis and pigmentation of his lips, fingers, and toes, he was diagnosed with PJS. After an inferior vena cava filter was placed, he underwent laparoscopic-assisted surgery. The polyps causing intussusception were resected as far as possible without intestinal resection, since they had caused progressive anemia and might cause intestinal obstruction in the future. The patient was discharged from the hospital on postoperative day 9 without complications. Conclusions Laparoscopic-assisted disinvagination and polypectomy is a useful, minimally invasive treatment for multiple intussusceptions caused by small intestinal polyps in patients with PJS.