Aspects of digestive tract tumors in Down syndrome: a literature review

Melanoma and intellectual disability: do prognostic factors at diagnosis differ from general population?

BACKGROUND

Few melanoma cases are reported in individuals with intellectual disability (ID), and prognostic factors at diagnosis are unknown in this population. This work was designed to investigate whether prognostic factors at diagnostic are different in patients with ID compared with a general population.

METHODS

Melanoma cases retrieved from Hérault's Tumour Registry (HTR) from 1995 to 2015 were cross-referenced against a list of adult patients with ID, living in Hérault. Major prognostic factors were compared with those in non-ID melanoma patients included in HTR and in patients followed by Montpellier University Hospital and included in the Réseau pour la Recherche et l'Investigation Clinique sur le Mélanome (RIC-Mel) database.

RESULTS

Ten melanoma cases in individuals with ID were identified and compared with 3804 non-ID melanoma cases in HTR and 1024 non-ID melanoma cases included in RIC-Mel. Mean Breslow thickness at diagnosis was 4.6 mm in melanoma cases among those with ID versus 1.89 mm in HTR (P = 0.109) and 2.36 mm in RIC-Mel (P = 0.156). Stage at diagnosis was superior to stage IIB in 42.9% of ID cases versus 11.4% of non-ID cases in HTR (P < 0.05) and 8.5% in RIC-Mel (P < 0.05).

CONCLUSIONS

Melanomas in patients with ID had less favourable prognostic factors at diagnosis, including higher Breslow thickness and more advanced stage, than melanomas in non-ID patients. These adverse prognostic factors indicate a later diagnosis in this population, leading to a poorer prognosis. This work underlines the need to improve melanoma screening among individuals with ID.

Transcriptional regulation of miR-196b by ETS2 in gastric cancer cells

E26 transformation-specific sequence (ETS)-2 is a transcriptional modulator located on chromosome 21, alterations in its expression have been implicated with a reduced incidence of solid tumors in Down syndrome patients. MicroRNAs (miRNAs) are thought to participate in diverse biological functions; however, the regulation of miRNAs is not well characterized. Recently, we reported that miR-196b is highly expressed in gastric cancers. Herein, we demonstrate that miR-196b expression was significantly repressed by ETS2 during gastric cancer oncogenesis. We demonstrate that knockdown of endogenous ETS2 expression increases miR-196b expression. A genomic region between −751 and −824 bp upstream of the miR-196b transcriptional start site was found to be critical for the repression activity. This putative regulatory promoter region contains three potential ETS2-binding motifs. Mutations within the ETS2 binding sites blocked the repression activity of ETS2. Furthermore, knockdown of ETS2 or overexpression of miR-196b significantly induced migration and invasion in gastric cancer cells. In addition, alterations in ETS2 and miR-196b expression in gastric cancer cell lines affected the expression of epithelial–mesenchymal transition-related genes. The levels of vimentin, matrix metalloproteinase (MMP)-2 and MMP9 were drastically induced, but levels of E-cadherin were decreased in shETS2- or miR-196b-transfected cells. Our data indicate that ETS2 plays a key role in controlling the expression of miR-196b, and miR-196b may mediate the tumor suppressor effects of ETS2. We demonstrated that miR-196b was transcriptionally regulated by ETS2 and there was an inverse expression profile between miR-196b and ETS2 in clinical samples. This finding could be beneficial for the development of effective cancer diagnostic and alternative therapeutic strategies.

Benign and malignant tumors in Down syndrome: analysis of the 1514 autopsied cases in Japan

BACKGROUND

Down syndrome is known for its association with neoplasms. The aim of this study was to examine this association.

METHODS

We surveyed the association with benign and malignant neoplasms in Down syndrome patients registered in the Annual of Pathological Autopsy Cases of Japan (1974-2000), a database of autopsied cases operated by the Japanese Society of Pathology.

RESULTS

In a total of 1514 cases with Down syndrome, there were eight cases with 10 benign tumors (four male and four female) and 104 cases with malignant disorders (61 male, 42 female and one case with unrecorded sex), in which 87 cases with hematopoietic malignancies (83.7%) and 17 cases with solid tumors (16.3%), were identified. The association of gallbladder adenocarcinoma with a benign tumor of the colon was noted in one case, while a further two cases with double benign tumors were confirmed as well. No case with a double malignancy was found. Hematopoietic malignancies (87 cases) included 31 cases (35.6%) with acute myelocytic leukemia, 10 (11.4%) with acute lymphocytic leukemia and two (2.3%) with chronic myelocytic leukemia. The ratio of acute myelocytic leukemia to acute lymphocytic leukemia was 3.1 in the present study. A peak in the age distribution was at 0 years in our data in contrast to the previous data (at 1 year) for myelocytic leukemia. The 17 solid tumors identified included three hepatocellular carcinomas, three extrahepatic cholangiocarcinomas, two gallbladder adenocarcinomas, three brain tumors, and three seminomas.

CONCLUSION

We present new associations of benign and malignant tumors with Down syndrome.