SHMT2 Promotes Invasion and Migration of Breast Cancer Cells Through Binding to and Up-regulating HAX1 / 肿瘤防治研究

Objective To explore the molecular mechanism of SHMT2 regulating the invasion and migration of breast cancer cells. Methods Bioinformatics analysis was used to verify the role of SHMT2 in breast cancer tissues. Transwell assay was used to detect the changes of invasion and migration abilities of breast cancer cells. Co-immunoprecipitation, knockdown plasmid transfection and Western blot were used to determine the regulatory relationship between different proteins. Results Bioinformatics analysis showed that the expression level of SHMT2 in invasive breast cancer tissues was significantly higher than that in adjacent normal tissues (P < 0.001). The 5-year disease-specific survival and overall survival in the SHMT2 high expression group were significantly lower than those in the SHMT2 low expression group (both P < 0.001). Transwell assay showed that SHMT2 knockdown significantly reduced the invasion ability (t=5.375, P=0.0058) and migration ability (t=6.274, P=0.0033) of MCF7 cells. Western blot showed that SHMT2 could combine to HAX1, and knockdown of SHMT2 reduced the protein level of HAX1. Transwell assay showed that the inhibitory effect of SHMT2 knockdown on the migration of MCF7 cells could be reversed by overexpression of HAX1 (t=6.274, P=0.0033; t=8.041, P=0.0013), while SHMT2 inhibitor (SHIN1, 10 nmol/L) significantly inhibited the migration of MCF7 cells induced by SHMT2 overexpression (t=10.16, P=0.0005; t=8.741, P=0.0009). Conclusion SHMT2 was closely related to the poor prognosis of breast cancer, and was a key factor in the invasion and migration of breast cancer cells. The mechanism was that SHMT2 increased the invasion and migration ability of breast cancer cells by binding to and up-regulating HAX1. It was verified that SHMT2 inhibitor could significantly reduce the migration ability of breast cancer cells. This study explored the therapeutic potential of SHMT2 inhibitor in metastatic breast cancer, and found potential intervention targets for its clinical treatment.

miR-125b increases sensitivity of CD133+ colorectal cancer cells to cisplatin by down-regulating HAX-1 expression / 中国病理生理杂志

AIM:To investigate the role of miR-125b in regulating the sensitivity of CD133+ colorectal cancer cells to cisplatin.METHODS:The expression of miR-125b was detected by RT-qPCR in the routine SW480 cells and CD133+ SW480 cells.Flow cytometry analysis was performed to measure the percentage of CD133+ cell population in the SW480 cell line treated with miR-125b and cisplatin.MTT assay was performed to evaluate the effect of miR-125b on the cisplatin-induced cell death in the CD133+ SW480 cells.Bioinformatics and Western blot were performed to determine whether the expression of HAX-1 was regulated by miR-125b.JC-1 staining, Annexin V staining and Western blot analysis were used to study the pathway of apoptosis in the CD133+ SW480 cells co-treated with miR-125b and cisplatin.RESULTS:The expression of miR-125b was significantly lower in the CD133+ SW480 cells than that in the routine SW480 cells and normal colonic epithelial FHC cells.Treatment with cisplatin alone increased the percentage of CD133+ SW480 cell population.However, miR-125b significantly inhibited the enrichment of CD133+ cell population induced by cisplatin.In addition, the results of MTT assay showed that the anti-tumor effect of cisplatin was significantly enhanced when the miR-125b was transfected into the CD133+ SW480 cells.The results of Western blot indicated that the HAX-1 gene was the target of miR-125b.Furthermore, the apoptosis induced by the combination of miR-125b and cisplatin was dependent on the dysfunction of mitochondrial membrane, leading to the release of cytochrome C into the cytoplasm and the subsequently activation of apoptosis in the CD133+ SW480 cells.CONCLUSION:miR-125b increased the sensitivity of CD133+ colo-rectal cancer cells to cisplatin by down-regulating the expression of HAX-1.

Genetic diagnosis of a patient with non-syndromic variants of congenital neutropenia / 中华内科杂志

ObjectiveTo explore the procedures and methods for genetic diagnosis in one nonsyndromic variants of congenital neutropenia (NSVCN) patient and its pathogenic mutation.Methods Genomic DNA was prepared from one NSVCN patient who had progressed to chronic myelomonocytic leukemia and ELA2,HAX1,WASp and GFI1 genes were amplified and sequenced.Results A novel compound heterogeneous mutation consisting of two frame-shift mutations (c.430-1insG and c.655- 9del5bp) was found in HAX1 gene.ConclusionA practically genetic diagnosis procedure for NSVCN has been established,and the novel HAX1 gene mutation may contribute to the etiology of NSVCN.

Molecular Analysis of Two Cases of Severe Congenital Neutropenia / 대한진단검사의학회지

Severe congenital neutropenia is a rare hematological disease characterized by a selective decrease in circulating neutrophils, maturation arrest of granulocytic precursors at the promyelocyte stage, and recurrence of infections. A 2-month-old male infant (patient A) and a 14-month-old female child (patient B) were referred to our hospital due to severe neutropenia. Sequencing analysis of ELA2 and HAX1 genes was performed. Two single nucleotide polymorphisms of HAX1 gene were found. They were 5,104T-->G point mutation of exon 1 and 5,474A-->G point mutation of intron 1 in HAX1 gene. The mutation of ELA2 gene was not found. The patient A showed a good response to granulocyte colony-stimulating factor (G-CSF) treatment and the absolute neutrophil count recovered to 1,195/microliter. But the patient B showed a partial response to G-CSF treatment and experienced several episodes of herpetic gingivostomatitis, oral ulcer, acute pharyngotonsillitis and otitis media during follow-up.