Functional characterization of novel or yet uncharacterized ATP7B missense variants detected in patients with clinical Wilson's disease.

Wilson's disease (WD, MIM#277900) is an autosomal recessive disorder resulting in copper excess caused by biallelic variants in the ATP7B gene (MIM#606882) encoding a copper transporting P-type ATPase. ATP7B variants of unknown significance (VUS) are detected frequently, sometimes impeding a clear diagnosis. Functional analyses can help to classify these variants as benign or pathogenic. Additionally, variants already classified as (likely) pathogenic benefit from functional analyses to understand their pathomechanism, thus contribute to the development of personalized treatment approaches in the future. We described clinical features of six WD patients and functionally characterized five ATP7B missense variants (two VUS, three yet uncharacterized likely pathogenic variants), detected in these patients. We determined the protein level, copper export capacity, and cellular localization in an in vitro model and potential structural consequences using an ATP7B protein model based on AlphaFold. Our analyses give insight into the pathomechanism and allowed reclassification for the two VUS to likely pathogenic and for two of the three likely pathogenic variants to pathogenic.

Associations of serum levels of microRNA-371a-3p (M371) with risk factors for progression in nonseminomatous testicular germ cell tumours clinical stage 1.

PURPOSE: Lymphovascular invasion (LV1) and presence of > 50% embryonal carcinoma (> 50% EC) represent risk factors for progression in patients with clinical stage 1 (CS1) nonseminomatous (NS) testicular germ cell tumours. As serum levels of microRNA-371a-3p (M371) are capable of detecting small amounts of GCT, we evaluated if LV1 and > 50% EC are associated with M371 levels. METHODS: M371 serum levels were measured postoperatively in 153 NS CS1 patients and both pre- and postoperatively in 131 patients. We registered the following factors: age, tumour size, LV status, > 50% EC, teratoma in primary, preoperative elevation of classical tumour markers. M371 expression was compared among subgroups. The ability of M371 to predict LV1 was calculated by receiver operating characteristics (ROC) curves. Multiple regression analysis was used to look for associations of M371 levels with other factors. RESULTS: Postoperatively elevated M371 levels were found in 29.4% of the patients, but were neither associated with LV status nor with > 50% EC. Likewise, relative decrease of M371 was not associated. ROC analysis of postoperative M371 levels revealed an AUC of 0.5 for the ability to predict LV1 while preoperative M371 had an AUC of 0.732. Multiple regression analysis revealed significant associations of preoperative M371 levels with LV status (p = 0.003), tumour size (p = 0.001), > 50% EC (p = 0.004), and teratoma component (p = 0.045). CONCLUSION: Postoperatively elevated M371 levels are not associated with risk factors for progression in NS CS1 patients. However, the significant association of preoperative M371 expression with LV1 deserves further evaluation.

High Expression of microRNA-371a-3p in Cystic Fluid of Post-Chemotherapy Teratoma with Concurrent Normal Serum Levels in Patients with Non-Seminomatous Testicular Germ Cell Tumours.

BACKGROUND: MicroRNA-371a-3p (miR-371), the novel serum biomarker of testicular germ cell tumours (GCTs), is produced by undifferentiated subtypes of GCTs but not by teratoma. Cystic teratoma developing from retroperitoneal metastases of GCT subsequent to chemotherapy had been shown to contain high levels of classical serum tumour markers of GCT in the presence of normal marker levels in serum. To date, no information is available regarding the presence of miR-371 in the cystic fluid of residual teratoma after chemotherapy. METHODS: Four patients (age 18-26 years) undergoing retroperitoneal lymph node dissection (RPLND) for cystic residual masses resulting from chemotherapy of bulky retroperitoneal GCT had measurements of miR-371 in both serum and cystic fluid aspirated from surgical specimens. Measurement of the miR was performed with quantitative real-time PCR using miR-30b-5p as reference. Results were tabulated and analysed in a descriptive manner. RESULTS: Histologically, all of the surgical specimens involved teratoma only with no evidence of vital undifferentiated GCT tissue. All patients were cured. Prior to RPLND, miR-371 serum levels were not measurable or close to zero in all of the patients. Cystic fluid revealed elevated levels of miR-371 in 3 patients and traces of miR in one. CONCLUSIONS: The detection of miR-371 in the cystic fluid of teratoma is somewhat enigmatic since this GCT subtype usually does not express the miR. Two hypotheses may explain the finding: First, miR-371 molecules were released into the cystic fluid by active GCT tissue prior to chemotherapy. High levels were kept after regression of vital GCT tissue because the cystic lumen is without a specific drainage system. Second, teratoma cells lining the interior cyst wall may shed small amounts of miR-371 into the lumen. Because of the lacking drainage system, even small levels may accumulate. The present finding adds to the understanding of the biology of the novel biomarker of GCT.

The Novel Biomarker of Germ Cell Tumours, Micro-RNA-371a-3p, Has a Very Rapid Decay in Patients with Clinical Stage 1.

BACKGROUND: Accumulating evidence suggests serum levels of microRNA (miR)-371a-3p to be a novel tumour marker of testicular germ cell tumours (GCTs). Presently, there is only limited information regarding the velocity of decline of serum levels in response to treatment. PATIENTS AND METHODS: Twenty-four patients with testicular GCT (20 seminoma, 4 nonseminoma, median age 40 years) with clinical stage 1 had measurements of serum levels of miR-371a-3p preoperatively and repeatedly on the following 3 days. Three had additional tests done within 24 h after surgery. Measurement results were analysed using descriptive statistical methods. RESULTS: Serum levels dropped to 2.62, 1.27, and 0.47% of the preoperative level within 1, 2, and 3 days, respectively. The computed half-life amounts to 3.7-7 h. The velocity of decay is significantly associated with tumour size. CONCLUSIONS: Serum-levels of miR-371a-3p have a short half-life of less than 12 h. The rapid decay after treatment represents a valuable feature confirming the usefulness of miR-371a-3p as a valuable serum biomarker of GCT.

Graded expression of microRNA-371a-3p in tumor tissues, contralateral testes, and in serum of patients with testicular germ cell tumor.

Background: Serum levels of microRNA-371a-3p represent a specific tumor marker of testicular germ cell tumors (GCTs) but the origin of circulating miR-371a-3p is not finally resolved. The correlation between miR-levels in tissue and serum is unclear. Results: MiR-levels in GCT tissue are 399-fold higher than in contralateral testicular tissue and 5843-fold higher than in non-testicular tissue. MiR tissue levels correlate with corresponding serum levels (r 2 = 0.181). ISH detected miR-371a-3p intracellularly in GCT cells except teratoma. A low expression was also detected in normal testicular germ cells. Conclusions: Circulating miR-371a-3p is specifically derived from GCT tissue. The miR is present in GCT cells except teratoma. A low expression is also found in normal testicular tissue but not in non-testicular tissue. MiR-371a-3p levels in tissue and serum correlate significantly. This study underscores the usefulness of serum miR-371a-3p as tumor marker of GCT. Patients and methods: Expression levels of miR-371a-3p were concurrently measured in tissues of GCT, contralateral testes ( n = 38), and in serum ( n = 36) with real time PCR. For control, 5 healthy testicles and 4 non-testicular tissue samples were examined. MiR-levels were compared using descriptive statistical methods. We also performed in situ hybridization (ISH) of GCT tissue with a probe specific for miR-371a-3p.