Two case reports of pilot percutaneous cryosurgery in familial multiple endocrine neoplasia type 1

Modeling MEN1 with Patient-Origin iPSCs Reveals GLP-1R Mediated Hypersecretion of Insulin

Multiple endocrine neoplasia type 1 (MEN1) is an inherited disease caused by mutations in the MEN1 gene encoding a nuclear protein menin. Among those different endocrine tumors of MEN1, the pancreatic neuroendocrine tumors (PNETs) are life-threatening and frequently implicated. Since there are uncertainties in genotype and phenotype relationship and there are species differences between humans and mice, it is worth it to replenish the mice model with human cell resources. Here, we tested whether the patient-origin induced pluripotent stem cell (iPSC) lines could phenocopy some defects of MEN1. In vitro β-cell differentiation revealed that the percentage of insulin-positive cells and insulin secretion were increased by at least two-fold in MEN1-iPSC derived cells, which was mainly resulted from significantly higher proliferative activities in the pancreatic progenitor stage (Day 7-13). This scenario was paralleled with increased expressions of prohormone convertase1/3 (PC1/3), glucagon-like peptide-1 (GLP-1), GLP-1R, and factors in the phosphatidylinositol 3-kinase (PI3K)/AKT signal pathway, and the GLP-1R was mainly expressed in β-like cells. Blockages of either GLP-1R or PI3K significantly reduced the percentages of insulin-positive cells and hypersecretion of insulin in MEN1-derived cells. Furthermore, in transplantation of different stages of MEN1-derived cells into immune-deficient mice, only those β-like cells produced tumors that mimicked the features of the PNETs from the original patient. To the best of our knowledge, this was the first case using patient-origin iPSCs modeling most phenotypes of MEN1, and the results suggested that GLP-1R may be a potential therapeutic target for MEN1-related hyperinsulinemia.

Long-term follow-up and novel splice donor mutation in MEN1 in a Chinese family

Heterozygous germline mutation of the MEN1 tumor suppressor gene is responsible for multiple endocrine neoplasia type 1. Parathyroid and thoracic neuroendocrine tumor specimens and DNA from two Han Chinese MEN1 family patients were analyzed using whole exome and Sanger sequencing. The proband (II-3) was sequentially diagnosed with pituitary adenoma, pancreatic tumor, adrenal cortical tumor, abdominal lipoma, and parathyroid adenoma during the 6-year follow-up. The son of the proband (III-6) was also diagnosed with a thoracic neuroendocrine tumor and a parathyroid adenoma during this period. Splice alterations were studied by RT-PCR and sequencing. The mutation impact was evaluated using bioinformatics. Sequence analysis revealed a novel splice donor mutation, MEN1 IVS9 + 1G > C, that changed the splicing mode of MEN1 to halt translation before two nuclear localization signals in the menin protein. Novel somatic mutations, MEN1 c.1402_1405delGAGG and c.286 C > T, were identified in the parathyroid adenoma of II-3 and thoracic neuroendocrine tumor of III-6, respectively, indicating a two-hit etiology of MEN1 syndrome. Our study revealed the clinical and genetic basis of MEN1 in this Han Chinese family and provides insight into MEN1 mechanisms, diagnosis, and management.

Testosterone improves the differentiation efficiency of insulin-producing cells from human induced pluripotent stem cells

Human induced pluripotent stem cells (hiPSCs) may provide potential resource for regenerative medicine research, including generation of insulin-producing cells for diabetes research and insulin production. Testosterone (T) is an androgen hormone which promotes protein synthesis and improves the management of type 2 diabetes in clinical studies. Concurrently, co-existed hyperandrogenism and hyperinsulinism is frequently observed in polycystic ovary syndrome, congenital adrenal hyperplasia and some of Wermer's syndrome. However, the relationship among androgens, insulin and the differentiation of pancreatic β cells is still not fully clear. Here we find that T improves the differentiation efficiency of insulin-producing cells from hiPSCs. The addition of T into routine differentiation formula for pancreatic β cells increases the differentiation efficiency from 12% to 35%. The administration of T promotes the expression of key genes associated with β cells differentiation including NGN3, NEUROD1 and INS. This finding benefits the ongoing process to optimize the differentiation protocol of pancreatic β cells from hiPSCs, and provides some degree of understanding the clinical management of T for type 2 diabetes.

Creating a patient carried Men1 gene point mutation on wild type iPSCs locus mediated by CRISPR/Cas9 and ssODN

A patient specific point mutation (c.1288G>T) of Men1 gene was introduced into wide type iPSC line with CRISPR/Cas9 and single-stranded donor oligonucleotides carrying the mutation. The mutated iPSC line has a heterozygous c.1288G>T mutation on exon-9 of Men1 that was confirmed by sequencing analysis. The karyotype of this line was normal and the pluripotency was demonstrated by its ability to differentiate into three germ layers. These artificially created Men1 mutation in wild type iPSC line will help to dissect out the molecular basis of two patients carried the same mutation from one family who were differentially represented hypoglycemia.

Generation of non-integrated induced pluripotent stem cells from a 59-year-old female with multiple endocrine neoplasia type 1 syndrome

Urine resource cells were collected from a 59-year-old female patient with multiple endocrine neoplasia type 1 syndrome (MEN1) for generating iPS cells with episomal plasmids carrying Oct4, Sox2, Klf4 and miR-302-367. The patient sustained a heterozygous G>T transition mutation on the exon 9 of Men1 gene that was confirmed by sequencing analysis on the obtained iPSC lines. Karyotyping indicated the chromosomes with normal appearances and numbers. Their pluripotency was demonstrated by gene expression, as well as their abilities for differentiating into three germ layers. This cell line provides an ideal model for studying MEN1.

Generation of non-integrated induced pluripotent stem cells from a 23-year-old male with multiple endocrine neoplasia type 1 syndrome

Urine resource cells were collected from a 23-year-old male with multiple endocrine neoplasia type 1 syndrome (MEN1) for generating iPS cells with episomal plasmids. Two stable iPSC lines with free of episomal plasmid were established. The patient has a heterozygous G>T mutation on the exon 9 of Men1 gene that was confirmed by sequencing analysis on all resulted cell lines. Karyotyping indicated the chromosomes with normal appearances and numbers. Their pluripotency was demonstrated by gene expression and their abilities for differentiating into three germ layers. These iPSC lines provide valuable in vitro resources for pathological study on MEN1 syndrome.

Percutaneous ablation of pancreatic cancer

Pancreatic ductal adenocarcinoma is a highly aggressive tumor with an overall 5-year survival rate of less than 5%. Prognosis and treatment depend on whether the tumor is resectable or not, which mostly depends on how quickly the diagnosis is made. Chemotherapy and radiotherapy can be both used in cases of non-resectable pancreatic cancer. In cases of pancreatic neoplasm that is locally advanced, non-resectable, but non-metastatic, it is possible to apply percutaneous treatments that are able to induce tumor cytoreduction. The aim of this article will be to describe the multiple currently available treatment techniques (radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation), their results, and their possible complications, with the aid of a literature review.

Clinical and Genetic Analysis of Multiple Endocrine Neoplasia Type 1-Related Primary Hyperparathyroidism in Chinese

Objective

Multiple endocrine neoplasia type 1-related primary hyperparathyroidism (MHPT) differs in many aspects from sporadic PHPT (SHPT). The aims of this study were to summarize the clinical features and genetic background of Chinese MHPT patients and compare the severity of the disease with those of SHPT.

Design and Methods

A total of 40 MHPT (27 sporadic, 7 families) and 169 SHPT cases of Chinese descent were retrospectively analyzed. X-rays and ultrasound were used to assess the bone and urinary system. Dual energy x-ray absorptiometry (DXA) were performed to measure bone mineral density (BMD). Besides direct sequencing of the MEN1 and CDKN1B genes, multiplex ligation-dependent probe amplification (MLPA) was used to screen gross deletion for the MEN1 gene.

Results

Compared with SHPT patients, MHPT patients showed lower prevalence of typical X-ray changes related to PHPT (26.3% vs. 55.7%, P = 0.001) but higher prevalence of urolithiasis/renal calcification (40.2% vs. 60.0%, P = 0.024). MHPT patients showed higher phosphate level (0.84 vs. 0.73mmol/L, P<0.05) but lower ALP (103.0 vs. 174.0U/L, P<0.001) and PTH (4.0 vs. 9.8×upper limit, P<0.001) levels than SHPT patients. There were no significant differences in BMD Z-scores at the lumbar spine and femoral neck between the two groups. Mutations in the MEN1 gene were detected in 27 MHPT cases. Among the nine novel mutations were novel, one of them involved the deletion of exon 5 and 6.

Conclusions

MHPT patients experienced more common kidney complications but less skeletal issues, and a milder biochemical manifestation compared with SHPT patients. MEN1 mutation detection rate was 79.4% and 9 of the identified mutations were novel.