Overexpression of FAM46A, a Non-canonical Poly(A) Polymerase, Promotes Hemin-Induced Hemoglobinization in K562 Cells

Classification of osteogenesis imperfecta: Importance for prophylaxis and genetic counseling

Osteogenesis imperfecta (OI) is a genetically heterogeneous monogenic disease characterized by decreased bone mass, bone fragility, and recurrent fractures. The phenotypic spectrum varies considerably ranging from prenatal fractures with lethal outcomes to mild forms with few fractures and normal stature. The basic mechanism is a collagen-related defect, not only in synthesis but also in folding, processing, bone mineralization, or osteoblast function. In recent years, great progress has been made in identifying new genes and molecular mechanisms underlying OI. In this context, the classification of OI has been revised several times and different types are used. The Sillence classification, based on clinical and radiological characteristics, is currently used as a grading of clinical severity. Based on the metabolic pathway, the functional classification allows identifying regulatory elements and targeting specific therapeutic approaches. Genetic classification has the advantage of identifying the inheritance pattern, an essential element for genetic counseling and prophylaxis. Although genotype-phenotype correlations may sometimes be challenging, genetic diagnosis allows a personalized management strategy, accurate family planning, and pregnancy management decisions including options for mode of delivery, or early antenatal OI treatment. Future research on molecular pathways and pathogenic variants involved could lead to the development of genotype-based therapeutic approaches. This narrative review summarizes our current understanding of genes, molecular mechanisms involved in OI, classifications, and their utility in prophylaxis.

Family with sequence similarity 46 member a confers chemo-resistance to ovarian carcinoma via TGF-β/Smad2 signaling

Ovarian cancer is the most lethal malignancy with depressive 5-year survival rate, mainly due to patients with advanced stages experience tumor recurrence and resistance to the current chemotherapeutic agents. Thus, exploring the underlying molecular mechanisms involved in chemo-resistance is crucial for management of treatment to improve therapeutic outcomes. In the current study, we found overexpression of FAM46A in ovarian cancer patients demonstrated an aggressive phenotype and poor outcome. Furthermore, FAM46A overexpression in ovarian cancer cells induces higher CDDP resistance. However, inhibition of FAM46A sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. Mechanically, upregulation of FAM46A activated transforming growth factor-β (TGF-β)/Smad signaling and upregulated the levels of nuclear Smad2. Taken together, our results highlight the important oncogenic role of FAM46A in ovarian cancer progression and might provide a potential clinical target for patients with chemo resistant ovarian cancer.

Tent5a modulates muscle fiber formation in adolescent idiopathic scoliosis via maintenance of myogenin expression

OBJECTIVE

Paravertebral muscle asymmetry may be involved in the pathogenesis of adolescent idiopathic scoliosis (AIS), and the Tent5a protein was recently identified as a novel active noncanonical poly(A) polymerase. We, therefore, explored the function of the AIS susceptibility gene Tent5a in myoblasts.

MATERIALS AND METHODS

RNA-seq of AIS paravertebral muscle was performed, and the molecular differences in paravertebral muscle were investigated. Twenty-four AIS susceptibility genes were screened, and differential expression of Tent5a in paravertebral muscles was confirmed with qPCR and Western blot. After the knockdown of Tent5a, the functional effects of Tent5a on C2C12 cell proliferation, migration, and apoptosis were detected by Cell Counting Kit-8 assay, wound-healing assay, and TUNEL assay, respectively. Myogenic differentiation markers were tested with immunofluorescence and qPCR in vitro, and muscle fiber formation was compared in vivo.

RESULTS

The AIS susceptibility gene Tent5a was differentially expressed in AIS paravertebral muscles. Tent5a knockdown inhibited the proliferation and migration of C2C12 cells and inhibited the maturation of type I muscle fibers in vitro and in vivo. Mechanistically, the expression of myogenin was decreased along with the suppression of Tent5a.

CONCLUSIONS

Tent5a plays an important role in the proliferation and migration of myoblasts, and it regulates muscle fiber maturation by maintaining the stability of myogenin. Tent5a may be involved in the pathogenesis of AIS by regulating the formation of muscle fiber type I.

FAM46A expression is elevated in glioblastoma and predicts poor prognosis of patients

OBJECTIVE

To study the expression of FAM46A in glioblastoma (GBM) and analyze its significance in predicting the prognosis of patients.

MATERIALS AND METHODS

mRNA expression and clinical data of patients with GBM were retrieved from ONCOMINE databases and The Cancer Genome Atlas (TCGA) database. Immunohistochemistry was performed in a tissue microarray including 110 GBM cases and 12 normal controls to determine the expression of FAM46A protein. Then, Kaplan-Meier curve and Cox regression model were used to investigate the relationship between FAM46A expression and clinical outcome. Coexpressed genes of FAM46A were analyzed by Linked Omics, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

Upregulated expression of FAM46A was found in both TCGA and our cohort. High FAM46A expression was associated with the poor prognosis of patients with GBM and could be identified as an independent risk factor for overall survival (HR = 1.652, p = 0.022). Further bioinformatics analysis revealed that FAM46A might be involved in cell motility and endoplasmic reticulum proteostasis and stress to promote GBM progression.

CONCLUSION

Our findings suggest that increased expression of FAM46A in GBM is a novel biomarker for predicting poor outcome of patients and that targeting FAM46A may serve as a potential therapy for this disease.