Esophageal cancer in a family with hamartomatous tumors and germline PTEN frameshift and SMAD7 missense mutations

Identification and Somatic Characterization of the Germline PTEN Promoter Variant rs34149102 in a Family with Gastrointestinal and Breast Tumors

Genetic variants located in non-coding regions can affect processes that regulate protein expression, functionally contributing to human disease. Germline heterozygous mutations in the non-coding region of the PTEN gene have been previously identified in patients with PTEN hamartoma tumor syndrome (PHTS) diagnosed with breast, thyroid, and/or endometrial cancer. In this study, we report a PTEN promoter variant (rs34149102 A allele) that was identified by direct sequencing in an Italian family with a history of gastroesophageal junction (GEJ) adenocarcinoma and breast cancer. In order to investigate the putative functional role of the rs34149102 A allele variant, we evaluated the status of PTEN alterations at the somatic level. We found that PTEN protein expression was absent in the GEJ adenocarcinoma tissue of the index case. Moreover, we detected the occurrence of copy number loss involving the PTEN rs34149102 major C allele in tumor tissue, revealing that the second allele was somatically inactivated. This variant is located within an active regulatory region of the PTEN core promoter, and in silico analysis suggests that it may affect the binding of the nuclear transcription factor MAZ and hence PTEN expression. Overall, these results reveal the functional role of the PTEN promoter rs34149102 A allele variant in the modulation of PTEN protein expression and highlight its contribution to hereditary cancer risk.

Gastrointestinal manifestations in PTEN hamartoma tumor syndrome

The PTEN hamartoma tumor syndrome (PHTS) is a heterogeneous set of multisystem disorders caused by germline pathogenic variants in the PTEN tumor suppressor gene. Manifestations include developmental anomalies and proliferative lesions. Evidence of involvement of the GI tract has accrued over time, leading to the incorporation of GI manifestations (multiple hamartomas, glycogenic acanthosis and colorectal cancer) into the diagnostic criteria. Polyps of the upper and lower GI tract are found in most adult patients and in a significant fraction of children. Polyps tend to be of mixed histology, with a predominance of hamartomas and ganglioneuromas. PHTS patients are also at increased risk of colorectal cancer, and surveillance by colonoscopy is advised starting at the age of 35-40 years. A number of additional manifestations, including eosinophilic gastrointestinal disorders, have been observed in few or single cases, and their association with PHTS has yet to be determined.

Esophageal cancer: Epidemiology, risk factors and screening

More than 600,000 people are diagnosed with esophageal cancer (EC) every year globally, and the five-year survival rate of EC is less than 20%. Two common histological subtypes of EC, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), have great geographical variations in incidence rates. About half of the world's EC was diagnosed in China and a majority of which belong to ESCC. Globally, the overall incidence rate of EC is decreasing. In some high-risk Asian regions, such as China, the incidence rate of ESCC has generally declined, potentially due to economic growth and improvement of diet habits. In some European high-income countries and the United States, the decline is mainly attributed to the decrease in smoking and drinking. The risk factors of EC are not well understood, and the importance of environmental and genetic factors in the pathogenesis is also unclear. The incidence and mortality of advanced EC can be reduced through early diagnosis and screening. White light endoscopy is still the gold standard in the current screening technology. This article reviews the epidemiology, risk factors, and screening strategies of EC in recent years to help researchers determine the most effective management strategies to reduce the risk of EC.

Esophageal Cancer: An Updated Review

The incidence of esophageal cancer (EC) is on the rise. With the distinct subtypes of adenocarcinoma and squamous cell carcinoma comes specific risk factors, and as a result, people of certain regions of the world can be more prone to a subtype. For example, squamous cell carcinoma of the esophagus has the highest incidence in eastern Africa and eastern Asia, with smoking being a major risk factor, whereas adenocarcinoma is more prevalent in North America and western Europe, with gastroesophageal reflux disease being a leading risk factor. With that being said, adenocarcinoma and squamous cell carcinoma have similar and unfortunately poor survival rates, partly because EC is prone to early metastasis given that the esophagus does not have a serosa, as well as the superficial nature of its lymphatics compared with the rest of the gastrointestinal tract. This makes early detection of the utmost importance, and certain patients have been shown to have the benefit of screening/surveillance endoscopies, including those with Barrett's esophagus, lye-induced/caustic strictures, tylosis, and Peutz-Jeghers syndrome. Until treatments significantly improve, identifying EC at the earliest stage will have the best success for patient outcomes, and further elucidation of its pathogenesis and risk factors may lead to identifying other high-risk groups that should be screened.

miR-125b prevent the progression of esophageal squamous cell carcinoma through the p38-MAPK signaling pathway

Background

To examine the clinical significance of miR-125b in esophageal squamous cell carcinoma (ESCC) and to research the effect of miR-125b on the biological function of ESCC cells and the relevant underlying mechanism.

Methods

The expression of miR-125b in ESCC tissues and cell lines were discovered by RT-PCR assay. The interrelation between miR-125b expression and clinicopathological parameters and the forecasting of ESCC patients were analyzed. CCK-8 method and Transwell methods were used to detect the increased growth, shifting, and irruption of ESCC cells. Bioinformatics analysis was applied to forecast the possible target genes of miR-125b and verified through dual-luciferase reporter gene assay. After that, the expression of p38-MAPK mRNA and protein were found out by RT-PCR and Western blot.

Results

The expression of miR-125b was down-regulated in ESCC tissues and cell lines (P<0.05). And the expression of miR-125b was closely about tumor differentiation, TNM level, and lymph node metastasis in ESCC patients. The low miR-125b formulation was closely related to rough forecasting in ESCC patients. Large scale expression of miR-125b can effectively decrease the acceleration, shifting, and irrupting strengths of ESCC cells. Bioinformatics analysis showed p38-MAPK was forecasted to be a potential mark of miR-125b, which was confirmed by dual luciferase assay, and extreme expression of miR-125b can stop the expression of p38-MAPK mRNA and protein.

Conclusions

miR-125b is down-regulated in ESCC. Moreover, its expression level is significant concerning tumor progression and prognosis in patients with ESCC. MiR-125b can stop the high growth and shifting of ESCC cells having p38-MAPK at target.

A Novel Smad7 Genetic Variant Mapping on the Genomic Region Targeted by Mongersen Is Associated with Crohn's Disease

Background: Down-regulation of Smad7 with a specific Smad7 antisense (AS) oligonucleotide-containing oral drug (Mongersen) was effective in pre-clinical studies and initial clinical trials in Crohn’s disease (CD) patients. A recent phase 3 trial was discontinued due to an apparent inefficacy of the drug, but factors contributing to the failure of this study remain unknown. Here, we analysed the frequency in CD of rs144204026 C/T single nucleotide polymorphism (SNP), which maps on the corresponding region targeted by the Smad7 AS contained in the Mongersen formulation and examined whether such a variant allele affects the ability of Smad7 AS to knockdown Smad7. Methods: rs144204026 SNP frequency was evaluated in two independent Italian cohorts of Crohn’s disease patients and normal controls. Genotyping was performed by allelic discrimination assay. Smad7 expression was evaluated in wild-type or heterozygous PBMCs treated with Smad7 AS. Results: No TT genotype was seen in CD patients and controls. Heterozygous genotype was more frequent in CD patients of both cohort 1 (11/235, 4.68%) and cohort 2 (8/122, 6.56%) as compared to controls (6/363, 1.65%; p = 0.029 and p = 0.01 respectively). Overall, a statistically significant association was observed between the T variant allele and CD patients’ susceptibility (p = 0.008; OR = 3.28, 95%CI: 1.3–8.3). Smad7 AS down-regulated Smad7 RNA independently of the presence of the variant allele. Conclusions: This is the first study to show an association between Smad7 rs144204026 SNP and CD patients. Data indicate that such a variant does not negatively influence the in vitro inhibitory effect of Smad7 AS on Smad7.

A Systematic Literature Review of Whole Exome and Genome Sequencing Population Studies of Genetic Susceptibility to Cancer

The application of next-generation sequencing (NGS) technologies in cancer research has accelerated the discovery of somatic mutations; however, progress in the identification of germline variation associated with cancer risk is less clear. We conducted a systematic literature review of cancer genetic susceptibility studies that used NGS technologies at an exome/genome-wide scale to obtain a fuller understanding of the research landscape to date and to inform future studies. The variability across studies on methodologies and reporting was considerable. Most studies sequenced few high-risk (mainly European) families, used a candidate analysis approach, and identified potential cancer-related germline variants or genes in a small fraction of the sequenced cancer cases. This review highlights the importance of establishing consensus on standards for the application and reporting of variants filtering strategies. It also describes the progress in the identification of cancer-related germline variation to date. These findings point to the untapped potential in conducting studies with appropriately sized and racially diverse families and populations, combining results across studies and expanding beyond a candidate analysis approach to advance the discovery of genetic variation that accounts for the unexplained cancer heritability.

Autism Linked to Increased Oncogene Mutations but Decreased Cancer Rate

Autism spectrum disorder (ASD) is one phenotypic aspect of many monogenic, hereditary cancer syndromes. Pleiotropic effects of cancer genes on the autism phenotype could lead to repurposing of oncology medications to treat this increasingly prevalent neurodevelopmental condition for which there is currently no treatment. To explore this hypothesis we sought to discover whether autistic patients more often have rare coding, single-nucleotide variants within tumor suppressor and oncogenes and whether autistic patients are more often diagnosed with neoplasms. Exome-sequencing data from the ARRA Autism Sequencing Collaboration was compared to that of a control cohort from the Exome Variant Server database revealing that rare, coding variants within oncogenes were enriched for in the ARRA ASD cohort (p<1.0 x 10(-8)). In contrast, variants were not significantly enriched in tumor suppressor genes. Phenotypically, children and adults with ASD exhibited a protective effect against cancer, with a frequency of 1.3% vs. 3.9% (p<0.001), but the protective effect decreased with age. The odds ratio of neoplasm for those with ASD relative to controls was 0.06 (95% CI: 0.02, 0.19; p<0.0001) in the 0 to 14 age group; 0.35 (95% CI: 0.14, 0.87; p = 0.024) in the 15 to 29 age group; 0.41 (95% CI: 0.15, 1.17; p = 0.095) in the 30 to 54 age group; and 0.49 (95% CI: 0.14, 1.74; p = 0.267) in those 55 and older. Both males and females demonstrated the protective effect. These findings suggest that defects in cellular proliferation, and potentially senescence, might influence both autism and neoplasm, and already approved drugs targeting oncogenic pathways might also have therapeutic value for treating autism.