Inherited colorectal cancer syndromes

Muons, mutations, and planetary shielding

Life on earth is protected from astrophysical cosmic rays by the heliospheric magnetic and slowly varying geomagnetic fields, and by collisions with oxygen and nitrogen molecules in the atmosphere. The collisions generate showers of particles of lesser energy; only muons, a charged particle with a mass between that of an electron and a proton, can reach earth's surface in substantial quantities. Muons are easily detected, used to image interior spaces of pyramids, and known to limit the stability of qubits in quantum computing; yet, despite their charge, average energy of 4 GeV and ionizing properties, muons are not considered to affect chemical reactions or biology. In this Perspective the potential damaging effects of muons on DNA, and hence the repercussions for evolution and disease, are examined. It is argued here that the effect of muons on life through DNA mutations should be considered when investigating the protection provided by the magnetic environment and atmosphere from cosmic rays on earth and exoplanets.

The Characterization and Outcomes of Colorectal Malignancy in Patients ≤40 Years of Age: A Single-Center Experience

BACKGROUND

Implementation of screening modalities has led to a decreased incidence of colorectal malignancies. Unfortunately, overall incidence has remained unchanged as cases have increased in patients below the suggested screening age. Therefore, we evaluated characteristics and oncological outcomes of malignancies in patients ≤40 years of age.

METHODS

Single-center retrospective analysis of prospectively collected data of malignancies in patients ≤40 years evaluated in our institution between 2010 and 2016. Basic descriptors for demographic, clinical, histologic, and genetic data were collected. Disease-free survival (DFS) and 5-year overall survival (OS) were compared for patients between 30-40 years and <30 years.

RESULTS

Fifty-six patients ≤40 years were identified, 44 of whom (96.5%) had adenocarcinomas. Most common malignancy location was the rectum (64.3%). Despite aggressive tumor characteristics such as moderate/poor differentiation (88.6%), lymphovascular invasion (26.8%), perineural invasion (21.4%), and advanced tumor stage T3/T4 (60.7%), OS rate was 94.6%. Both age groups had similar oncologic characteristics. There was a trend toward worse OS (2/11 and 1/45, P = .06) but not for DFS (7/11 and 15/43, P = .18) in patients <30 years of age compared to 30-40 years. There were no differences in OS (3/44 vs 0/88, P = .44) or DFS (17/42 vs 3/8, P = .80) between sporadic vs non-sporadic malignancies, respectively.

CONCLUSIONS

Patients ≤40 years of age with malignancy have advanced tumor stages and aggressive tumor characteristics at diagnosis. Although there is higher OS risk for patients <30 compared to those aged 30-40 years, no differences were found for DFS between these two groups.

Evaluation of antitumor effects of VEGFR-2 inhibitor F16 in a colorectal xenograft model

OBJECTIVES

Colorectal cancer (CRC) is the third most prevalent type of cancer in the United States. The treatment options for cancer include surgery, chemotherapy, radiation, and/or targeted therapy, which show significant improvement in overall survival. Among the various available treatments, antagonizing VEGF/VEGFR-2 pathways have shown effectiveness in limiting colorectal cancer growth and improving clinical outcomes. In this regard, we hypothesized that F16, a novel VEGFR-2 inhibitor, would control colorectal cancer growth by blocking the VEGFR-2 singling pathway in both in vitro and in vivo conditions. Therefore, the current study was aimed to analyze the efficacy of F16 on the growth of Colo 320DM cells under in vitro and in vivo conditions.

RESULTS

Human RT² profiler PCR array analysis results clearly showed that angiogenesis and anti-apoptosis-related gene expressions were significantly reduced in HUVEC cells after F16 (5 μM) treatment. In addition, Western blot results revealed that F16 attenuated the downstream signaling of the VEGFR-2 pathway in HUVEC cells by up-regulating the p53 and p21 levels and down-regulating the p-AKT and p-FAK levels. Accordingly, F16 confirmed potent cytotoxic effects against the cell viability of Colo 320DM tumors, with an IC₅₀ value of 9.52 ± 1.49 µM. Furthermore, treatment of mice implanted with Colo 320DM xenograft tumors showed a significant reduction in tumor growth and increases in survival rate compared to controls. Immunohistochemistry analysis of tumor tissues showed a reduction in CD31 levels also in F16 treated groups.

CONCLUSIONS

These results justify further evaluation of F16 as a potential new therapeutic agent for treating colorectal cancers.

Consumption of Select Dietary Emulsifiers Exacerbates the Development of Spontaneous Intestinal Adenoma

Inflammation is a well-characterized critical driver of gastrointestinal cancers. Previous findings have shown that intestinal low-grade inflammation can be promoted by the consumption of select dietary emulsifiers, ubiquitous component of processed foods which alter the composition and function of the gut microbiota. Using a model of colitis-associated cancer, we previously reported that consumption of the dietary emulsifiers carboxymethylcellulose or polysorbate-80 exacerbated colonic tumor development. Here, we investigate the impact of dietary emulsifiers consumption on cancer initiation and progression in a genetical model of intestinal adenomas. In APC^min mice, we observed that dietary emulsifiers consumption enhanced small-intestine tumor development in a way that appeared to be independent of chronic intestinal inflammation but rather associated with emulsifiers' impact on the proliferative status of the intestinal epithelium as well as on intestinal microbiota composition in both male and female mice. Overall, our findings further support the hypothesis that emulsifier consumption may be a new modifiable risk factor for colorectal cancer (CRC) and that alterations in host-microbiota interactions can favor gastrointestinal carcinogenesis in individuals with a genetical predisposition to such disorders.