Novel TMEM127 Variant Associated to Bilateral Phaeochromocytoma with an Uncommon Clinical Presentation

miRNA-23b-5p affects the proliferation, migration and invasion of osteosarcoma by targeting TMEM127

BACKGROUND

Osteosarcoma (OS) has become one of the highest mortality cancers in the world due to its late diagnosis, rapid metastasis and rapid recurrence. MicroRNAs can regulate a variety of signaling pathwas involved in cancer development, such as cell proliferation, apoptosis and migration.

OBJECTIVE

In this study, we studied the biological effects and molecular regulation of mir-23b-5p on human osteosarcoma cells.

METHODS

The proliferation of mir-23b-5p in osteosarcoma was measured by CCK8 method and EDU method. In addition, the target population was screened through the database, and the luciferase reporter gene was used to determine the association between miRNA and target gene TMEM127. We verified this result by Western blot.

RESULTS

We found that mir-23b-5p promotes the progression of osteosarcoma by regulating TMEM127.

CONCLUSIONS

The results of this study show that mir-23b-5p affects the proliferation, metastasis and invasion of OS by targeting TMEM127.

Genotype-Phenotype Features of Germline Variants of the TMEM127 Pheochromocytoma Susceptibility Gene: A 10-Year Update

PURPOSE

This work aimed to evaluate genotype-phenotype associations in individuals carrying germline variants of transmembrane protein 127 gene (TMEM127), a poorly known gene that confers susceptibility to pheochromocytoma (PHEO) and paraganglioma (PGL).

DESIGN

Data were collected from a registry of probands with TMEM127 variants, published reports, and public databases.

MAIN OUTCOME ANALYSIS

Clinical, genetic, and functional associations were determined.

RESULTS

The cohort comprised 110 index patients (111 variants) with a mean age of 45 years (range, 21-84 years). Females were predominant (76 vs 34, P < .001). Most patients had PHEO (n = 94; 85.5%), although PGL (n = 10; 9%) and renal cell carcinoma (RCC, n = 6; 5.4%) were also detected, either alone or in combination with PHEO. One-third of the cases had multiple tumors, and known family history was reported in 15.4%. Metastatic PHEO/PGL was rare (2.8%). Epinephrine alone, or combined with norepinephrine, accounted for 82% of the catecholamine profiles of PHEO/PGLs. Most variants (n = 63) occurred only once and 13 were recurrent (2-12 times). Although nontruncating variants were less frequent than truncating changes overall, they were predominant in non-PHEO clinical presentations (36% PHEO-only vs 69% other, P < .001) and clustered disproportionately within transmembrane regions (P < .01), underscoring the relevance of these domains for TMEM127 function. Integration of clinical and previous experimental data supported classification of variants into 4 groups based on mutation type, localization, and predicted disruption.

CONCLUSIONS

Patients with TMEM127 variants often resemble sporadic nonmetastatic PHEOs. PGL and RCC may also co-occur, although their causal link requires further evaluation. We propose a new classification to predict variant pathogenicity and assist with carrier surveillance.

Pheochromocytoma Due to TMEM127 Mutation - The Importance of Genetic Testing for Clinical Decision

Apreviously healthy 53-year-old woman presented with new onset arterial hypertension diagnosed during workup for daily pulsatile bilateral frontal headaches and paroxysmal episodes of fatigue, palpitations and sweating. High urinary metanephrines were detected and an abdominal magnetic resonance image evidenced two nodular bilateral adrenal lesions and a left iliac focal lesion. ¹⁸F-FDG-PET/CT (fluorodeoxyglucose-positron emission tomography/computed tomography) scanning revealed mild-to-moderate uptake in both adrenal lesions and mild uptake in the iliac bone, whereas ¹²³I-metaiodobenzylguanide scintigraphy revealed uptake only in the right adrenal. CT-scan confirmed the heterogeneous nodular lesion on the right adrenal gland as suspicious for pheochromocytoma and a non-specific sclerotic lesion in the iliac. A right adrenalectomy was performed with posterior resolution of symptoms and normalisation of urinary metanephrines. Histology confirmed a pheochromocytoma and later a mutation of the TMEM127 gene was detected. The present case highlights the importance of genetic testing for pheochromocytoma in order to better guide the management of these patients.