ABSTRACT
Objective:To investigate the effects of plasma exosome-derived miR-20a-5p on bone metastases in estrogen receptor-positive breast cancer (ER (+) BC) by targeting PIK3R1.Methods:The data sets related to ER (+) BC bone metastasis were retrieved with the help of bioinformatics website, miR-20a-5p was included in the study. The plasma of 90 ER (+) BC patients and the corresponding healthy people were collected to detect the expression of PIK3R1 in the plasma, and exosomes were extracted from the plasma to detect expression of miR-20a-5p in exosomes. The dual-luciferase reporter assay was used to verify the targeting regulation relationship between miR-20a-5p and PIK3R1. The exosomes transfected with NC-inhibitor and miR-inhibitor or ER (+) BC cells transfected with si-NC and si-PIK3R1 were injected into the left ventricle of mice, respectively, and the bone tissue was scanned by Micro-CT and bone tissue TRAP staining was performed. After co-culturing NC-inhibitor and miR-inhibitor-transfected exosomes with si-NC and si-PIK3R1-transfected ER (+) BC cells, Western blot was used to detect the expression of osteoclast molecules c-fos and NFATc1.Results:qRT-PCR assay showed that compared with normal plasma exosomes (1±0.26) or cells (1±0.13) , miR-20a-5p was significantly increased in ER (+) BC plasma exosomes (1.49±0.27) ( t=12.40, P<0.001) and BC cell line MCF-7 (1.64±0.13) ( t=6.03, P=0.004) , BT474 (1.49±0.11) ( t=4.98, P=0.008) , T47D (1.98±0.15) ( t=8.55, P=0.001) . But compared with normal plasma exosomes (1±0.25) or cells (1±0.10) , expression of PIK3R1 in ER (+) BC plasma exosomes (0.69±0.24) ( t=8.48, P<0.001) and ER (+) BC cell lines MCF-7 (0.73±0.05) ( t=4.18, P=0.014) , BT474 (0.61±0.05) ( t=6.04, P=0.004) , and T47D (0.34±0.04) ( t=10.61, P<0.001) was inhibited. PIK3R1 was confirmed as a target gene of miR-20a-5p. Compared with mice in NC-inhibitor group, trabecular bone tissue volume ( t=3.32, P=0.029) , trabecular bone area volume ( t=6.24, P=0.003) , bone volume fraction ( t=7.35, P=0.002) and bone mineral density ( t=13.72, P<0.001) of mice in miR-inhibitor group were both increased, the number of mature osteoclasts was decreased. Compared with NC inhibitor group, expression of c-fos ( t=9.04, P=0.001) and NFATc1 ( t=13.42, P<0.001) in miR-inhibitor group was decreased. Compared with miR-inhibitor+si-NC group, trabecular bone tissue volume ( t=3.03, P=0.039) , trabecular bone area volume ( t=6.37, P=0.003) , bone volume fraction ( t=3.36, P=0.028) and bone mineral density ( t=6.92, P=0.002) were decreased, the number of mature osteoclasts was increased, and expressionof c-fos ( t=7.75, P= 0.002) and NFATc1 ( t=9.65, P=0.001) was increased in miR-inhibitor+si-PIK3R1 group. Conclusion:PlasmaExosome-derived miR-20a-5p from ER (+) BC patients promotes ER (+) BC bone metastasis by inhibiting the expression of PIK3R1.
ABSTRACT
The clinical data of a child with SHORT syndrome caused by PIK3R1 gene mutation in Children′s Hospital of Nanjing Medical University was retrospectively analyzed.The patient was a 11 years old and 5 months Chinese girl initially hospitalized due to polyuria, polyphagia and polydipsia in the past 2 months.Physical examination showed decreased subcutaneous fat on the face, a triangular-shaped face, ocular depression, a wide nose bridge, hypoplastic nasal alae, columnar depression in the low part of the nose, downturned lips, hyperpigmentation of the skin of the neck, axillae, cubital and popliteal fossae and groins (acanthosis nigricans). Besides, slight cubitus valgus and hyperextension were observed.Laboratory tests showed diabetes mellitus with insulin resistance.Whole exome sequencing identified a de novo heterozygous PIK3R1 mutation (c.1945C>T, p.Arg649Trp), SHORT syndrome is a rare autosomal dominant disorder, characterized by special facial appearance, lipodystrophy and insulin resistance.Molecular analysis of the PIK3R1 gene permits confirmation of the diagnosis.The patients with SHORT syndrome require multidisciplinary management, and early diagnosis can prevent complications and reduce the burden on the family.
ABSTRACT
BACKGROUND: Phosphoinositide-3-kinase, regulatory subunit 1 (PIK3R1) could regulate cancer cell proliferation important for cancer cell proliferation; however, its role in Hepatocellular carcinoma (HCC) remains largely unknown. Here, we investigated the role of PIK3R1 in HCC and examined the underlying molecular mechanisms. METHODS: The expression of PIK3R1 was evaluated by immunohistochemistry and qRT-PCR in a series of HCC tissues. The mRNA and protein expression of PIK3R1 was used by qRT-PCR and western blot assays in a series of human HCC cell lines, and then we choose MHCC97H and HCCLM3 cells as a model to investigate the effect of PIK3R1 on HCC progression. The effects of PIK3R1 knowdown on cell proliferation, migration, apoptosis of HCC were assessed by the MTT assay, clonogenic assays, wound healing assay and flow cytometry in vitro. Western blot assay was performed to assess the expression changes of PI3K/AKT/mTOR signaling pathway. RESULTS: Our results found that PIK3R1 was highly expressed in HCC tissues compared with adjacent normal tissues. Knockdown of PIK3R1 inhibited the proliferation, migration and promoted apoptosis of HCC cell lines. In addition, we proved that knockdown of PIK3R1 downregulated p-PI3K, p-AKT, and p-mTOR expressions in MHCC97H and HCCLM3 cells. CONCLUSIONS: In conclusion, PIK3R1 providing potential novel targets for the treatment of HCC.